[PATCH] v4l: bttv i2c oops fix

Don't try to access the i2c bus if the register wasn't successful.

Signed-off-by: Gerd Knorr <kraxel@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>