media: dvbsky: shut up a bogus warning

Smatch gives two bogus warnings on this driver:
	drivers/media/usb/dvb-usb-v2/dvbsky.c:336 dvbsky_s960_attach() error: uninitialized symbol 'i2c_adapter'.
	drivers/media/usb/dvb-usb-v2/dvbsky.c:459 dvbsky_s960c_attach() error: uninitialized symbol 'i2c_adapter'.

Shut them up.

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