snd_msnd_pcm() takes a pointer to a pointer of a PCM where if this parameter
is provided the newly allocated PCM is stored. All callers pass NULL though,
so remove the parameter. This makes the code a bit cleaner and shorter.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>