V4L: msp_attach must return 0 if no msp3400 was found.

V4L: msp_attach must return 0 if no msp3400 was found.

V4L: msp_attach must return 0 if no msp3400 was found.

Returning -1 causes the probe to stop, but it should just continue
instead. This patch fixes an annoying 'i2c_adapter i2c-7: Client
creation failed at 0x44 (-1)' kernel message that appeared in 2.6.20

(cherry picked from commit 3284b4e077cb2322754ea7455b8f8af7ce3777b8)

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>