V4L/DVB (11227): ce6230: avoid using unitialized var

drivers/media/dvb/dvb-usb/ce6230.c: In function ‘ce6230_i2c_xfer’:
drivers/media/dvb/dvb-usb/ce6230.c:107: warning: ‘ret’ may be used uninitialized in this function

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>