V4L/DVB (5528): Usbvision: reverting some i2c cleanups

usbvision-i2c.c: reverting some i2c cleanups in order to recover a safe state.
Acked-by: Dwaine Garden <DwaineGarden@rogers.com>

Signed-off-by: Thierry MERLE <thierry.merle@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>