Fixes gcc '-Wunused-but-set-variable' warnings:

sound/ppc/snd_ps3.c: In function 'snd_ps3_program_dma':
sound/ppc/snd_ps3.c:236:8: warning: variable 'start_vaddr' set but not used [-Wunused-but-set-variable]
sound/ppc/snd_ps3.c: In function 'snd_ps3_pcm_open':
sound/ppc/snd_ps3.c:529:6: warning: variable 'pcm_index' set but not used [-Wunused-but-set-variable]

They are never used and can be removed.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>