Segfault during endpoint write

I encountered a segfault during a USB endpoint write.

Unfortunately, I don't have much context beyond the following. In general, my expectation is that `gousb` should prevent any segfaults by proper management of the underlying connection, but maybe I have a misunderstanding of proper usage of the go package. From a review of the client code for `gousb`, there is no concurrent access that could potentially cause this.

```
SIGSEGV: segmentation violation
PC=0x7f6703537c49 m=4 sigcode=128 addr=0x0
signal arrived during cgo execution

goroutine 544 gp=0xc000682e00 m=4 mp=0xc0003ed808 [syscall]:
runtime.cgocall(0xa57cd0, 0xc0023d1548)
/usr/local/go/src/runtime/cgocall.go:167 +0x4b fp=0xc0023d1520 sp=0xc0023d14e8 pc=0x47c30b
github.com/google/gousb._Cfunc_submit(0x7f66b0004f00)
_cgo_gotypes.go:680 +0x45 fp=0xc0023d1548 sp=0xc0023d1520 pc=0x8cbb25
github.com/google/gousb.libusbImpl.submit.func1(...)
/workspaces/my_project/vendor/github.com/google/gousb/libusb.go:470
github.com/google/gousb.libusbImpl.submit({}, 0x7f66b0004f00)
/workspaces/my_project/vendor/github.com/google/gousb/libusb.go:470 +0x35 fp=0xc0023d1578 sp=0xc0023d1548 pc=0x8ce515
github.com/google/gousb.(*libusbImpl).submit(0xc0041f53b0?, 0x120e500?)
:1 +0x25 fp=0xc0023d1590 sp=0xc0023d1578 pc=0x8d1a65
github.com/google/gousb.(*usbTransfer).submit(0xc0041d6740)
/workspaces/my_project/vendor/github.com/google/gousb/transfer.go:51 +0x90 fp=0xc0023d15e0 sp=0xc0023d1590 pc=0x8c7b90
github.com/google/gousb.(*endpoint).transfer(0xc000822070, {0xcddd20, 0xc0041f53b0}, {0xc0041f6c00, 0x3f7, 0x1?})
/workspaces/my_project/vendor/github.com/google/gousb/endpoint.go:98 +0xf5 fp=0xc0023d1668 sp=0xc0023d15e0 pc=0x8c6515
github.com/google/gousb.(*OutEndpoint).WriteContext(...)
/workspaces/my_project/vendor/github.com/google/gousb/endpoint.go:170
```

Any expertise to help explain what would surface this would be helpful.