[media] radio-bcm2048: fix compiler warning

radio-bcm2048.c: In function 'bcm2048_i2c_driver_probe':
radio-bcm2048.c:2597:11: warning: variable 'skip_release' set but not used [-Wunused-but-set-variable]
  int err, skip_release = 0;
             ^

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>