unused variables in src/os.c

[krumelmonster]

Another issue arising from -Werror

/quasi-msys2/tectogen/ext/libsoundio/src/os.c: In function 'run_win32_thread':
/quasi-msys2/tectogen/ext/libsoundio/src/os.c:169:13: error: unused variable 'err' [-Werror=unused-variable]
  169 |     HRESULT err = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED);
      |             ^~~
/quasi-msys2/tectogen/ext/libsoundio/src/os.c: In function 'soundio_os_thread_destroy':
/quasi-msys2/tectogen/ext/libsoundio/src/os.c:268:14: error: unused variable 'ok' [-Werror=unused-variable]
  268 |         BOOL ok = CloseHandle(thread->handle);
      |              ^~
/quasi-msys2/tectogen/ext/libsoundio/src/os.c:266:15: error: unused variable 'err' [-Werror=unused-variable]
  266 |         DWORD err = WaitForSingleObject(thread->handle, INFINITE);
      |               ^~~
/quasi-msys2/tectogen/ext/libsoundio/src/os.c: In function 'soundio_os_init_mirrored_memory':
/quasi-msys2/tectogen/ext/libsoundio/src/os.c:621:10: error: variable 'ok' set but not used [-Werror=unused-but-set-variable]
  621 |     BOOL ok;
      |          ^~
/quasi-msys2/tectogen/ext/libsoundio/src/os.c: In function 'soundio_os_deinit_mirrored_memory':
/quasi-msys2/tectogen/ext/libsoundio/src/os.c:735:10: error: variable 'ok' set but not used [-Werror=unused-but-set-variable]
  735 |     BOOL ok;
      |          ^~
cc1.exe: all warnings being treated as errors
make[2]: *** [ext/libsoundio/CMakeFiles/libsoundio_static.dir/build.make:107: ext/libsoundio/CMakeFiles/libsoundio_static.dir/src/os.c.obj] Error 1
make[1]: *** [CMakeFiles/Makefile2:127: ext/libsoundio/CMakeFiles/libsoundio_static.dir/all] Error 2
make: *** [Makefile:136: all] Error 2