V4L/DVB: cx23885: i2c_wait_done returns 0 or 1, don't check for < 0 return value

Function i2c_wait_done() never returns negative values, so there is no
point in checking for them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>