V4L/DVB (7156): em28xx/em28xx-core.c: fix use of potentially uninitialized variable

drivers/media/video/em28xx/em28xx-core.c: In function 'em28xx_set_audio_source':
drivers/media/video/em28xx/em28xx-core.c:276: warning: 'no_ac97' may be used uninitialized in this function

This looks like a genuine bug to me.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>