Wishlish: fix compiler warnings about shadowed variables

@dtikhonov is already working on this.

Since Jan 6, 2026.

https://github.com/litespeedtech/lsquic/blob/342a9b35690ee6c879a9b2e2b02af9a2fe17a1c4/src/liblsquic/lsquic_handshake.c#L79

```
D:/lsquic/src/liblsquic/lsquic_handshake.c:796:55: warning: declaration shadows a variable in the global scope [-Wshadow]
796 | lsquic_enc_session_create_client (struct lsquic_conn *lconn, const char *domain,
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:874:55: warning: declaration shadows a variable in the global scope [-Wshadow]
874 | lsquic_enc_session_create_server (struct lsquic_conn *lconn, lsquic_cid_t cid,
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3162:55: warning: declaration shadows a variable in the global scope [-Wshadow]
3162 | const struct lsquic_conn *lconn,
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3691:31: warning: declaration shadows a variable in the global scope [-Wshadow]
3691 | const struct lsquic_conn *lconn, struct lsquic_packet_out *packet_out,
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3768:31: warning: declaration shadows a variable in the global scope [-Wshadow]
3768 | struct lsquic_conn *const lconn = enc_session->es_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3806:29: warning: declaration shadows a variable in the global scope [-Wshadow]
3806 | struct lsquic_conn *lconn, struct lsquic_packet_out *packet_out)
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3851:71: warning: declaration shadows a variable in the global scope [-Wshadow]
3851 | gquic_esf_set_conn (enc_session_t *enc_session_p, struct lsquic_conn *lconn)
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:3979:31: warning: declaration shadows a variable in the global scope [-Wshadow]
3979 | struct lsquic_conn *const lconn = enc_session->es_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^
D:/lsquic/src/liblsquic/lsquic_handshake.c:4164:71: warning: declaration shadows a variable in the global scope [-Wshadow]
4164 | struct lsquic_engine_public *enpub, const struct lsquic_conn *lconn,
| ^

D:/lsquic/src/liblsquic/lsquic_handshake.c:79:40: note: previous declaration is here
79 | static const struct lsquic_conn *const lconn = &dummy_lsquic_conn;
| ^

15 warnings generated.

```

```
D:/lsquic/src/liblsquic/lsquic_full_conn_ietf.c:7086:9: warning: declaration shadows a local variable [-Wshadow]
7086 | LSQ_DEBUGC("current SCID: %"CID_FMT, CID_BITS(CN_SCID(&conn->ifc_conn)));
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:229:27: note: expanded from macro 'LSQ_DEBUGC'
229 | #define LSQ_DEBUGC(...) LSQ_LOGC(LSQ_LOG_DEBUG, __VA_ARGS__)
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:208:25: note: expanded from macro 'LSQ_LOGC'
208 | # define LSQ_LOGC LSQ_LOG2C
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:159:18: note: expanded from macro 'LSQ_LOG2C'
159 | char cidbuf_[MAX_CID_LEN * 2 + 1]; \
| ^
D:/lsquic/src/liblsquic/lsquic_full_conn_ietf.c:7061:10: note: previous declaration is here
7061 | char cidbuf_[MAX_CID_LEN * 2 + 1];
| ^
D:/lsquic/src/liblsquic/lsquic_full_conn_ietf.c:7087:9: warning: declaration shadows a local variable [-Wshadow]
7087 | LSQ_DEBUGC("packet in DCID: %"CID_FMT"; changed: %d",
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:229:27: note: expanded from macro 'LSQ_DEBUGC'
229 | #define LSQ_DEBUGC(...) LSQ_LOGC(LSQ_LOG_DEBUG, __VA_ARGS__)
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:208:25: note: expanded from macro 'LSQ_LOGC'
208 | # define LSQ_LOGC LSQ_LOG2C
| ^
D:/lsquic/src/liblsquic\lsquic_logger.h:159:18: note: expanded from macro 'LSQ_LOG2C'
159 | char cidbuf_[MAX_CID_LEN * 2 + 1]; \
| ^
D:/lsquic/src/liblsquic/lsquic_full_conn_ietf.c:7061:10: note: previous declaration is here
7061 | char cidbuf_[MAX_CID_LEN * 2 + 1];
| ^

```