audio/openal-soft: Fix crashes in the sndio backend.

Details:

• Backport the upstream commits at https://github.com/kcat/openal-soft/commit/620836f173ae6fc4505d0634984e0f2c46166367 https://github.com/kcat/openal-soft/commit/1fd4c865fc084f134363db5155361d5483679235 https://github.com/kcat/openal-soft/commit/a4b0a3d7b3ec271243cfda4780e567e49f2b37b7

MFH: 2021Q4