ALSA: hda/hdmi: Use single mutex unlock in error paths

Instead of calling mutex_unlock() at each error path multiple times,
take the standard goto-and-a-single-unlock approach.  This will
simplify the code and make easier to find the unbalanced mutex locks.

No functional changes, but only the code readability improvement as a
preliminary work for further changes.

Signed-off-by: Takashi Iwai <tiwai@suse.de>