misleading engine error on bind_qat() failure

I was debugging what is wrong with the engine .so when openssl returns:

```
# openssl engine -c -t -vvv qat-hw
140402102523712:error:260B606D:engine routines:dynamic_load:init failed:../crypto/engine/eng_dyn.c:487:
140402102523712:error:2606A074:engine routines:ENGINE_by_id:no such engine:../crypto/engine/eng_list.c:421:id=qat-hw
```

with additional debug it shows
```
# openssl engine -c -t -vvv qat-hw
[WARN][3882832.072215] PID [9] Thread [7fb1e9725740][e_qat.c:857:bind_qat()] QAT Warnings enabled.
[DEBUG][3882832.072264] PID [9] Thread [7fb1e9725740][e_qat.c:858:bind_qat()] QAT Debug enabled.
[WARN][3882832.072270] PID [9] Thread [7fb1e9725740][e_qat.c:859:bind_qat()] qat-hw - Reference implementation of QAT crypto engine(qat_hw) v0.6.11
[WARN][3882832.072293] PID [9] Thread [7fb1e9725740][e_qat.c:879:bind_qat()] Qat device not available
140402102523712:error:260B606D:engine routines:dynamic_load:init failed:../crypto/engine/eng_dyn.c:487:
140402102523712:error:2606A074:engine routines:ENGINE_by_id:no such engine:../crypto/engine/eng_list.c:421:id=qat-hw
```

Can we update the error code on `bind_qat()` failure?
https://github.com/intel/QAT_Engine/blob/d9950465ae949d1570581de3ca8a2e0072eaee5d/e_qat.c#L1059-L1063