dlmisc.c: Avoid double unlock in snd_dlobj_cache_get0()

[GitHub pull_request - opened <github@xxxxxxxxxxxxxxxx>]

alsa-project/alsa-lib pull request #182 was opened from johado:

Remove call to snd_dlobj_unlock() in snd_dlobj_cache_get0()
All lock/unlock is done by callers of the function.

Fixes: https://github.com/alsa-project/alsa-lib/issues/181

Request URL   : https://github.com/alsa-project/alsa-lib/pull/182
Patch URL     : https://github.com/alsa-project/alsa-lib/pull/182.patch
Repository URL: https://github.com/alsa-project/alsa-lib