[PATCH] isdn_v110 warning fix

Here's a small warning fix for drivers/isdn/i4l/isdn_v110.c
 drivers/isdn/i4l/isdn_v110.c:523: warning: `ret' might be used uninitialized in this function

In addition to Karsten Keil signing off on the patch, Thomas Pfeiffer also
commented on the patch, saying
"initializing ret with the value zero is correct and should be done."

Please apply.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>