V4L/DVB: dvb/stv6110x: cleanup error handling

The "stv6110x" is NULL so we can just return directly without calling
kfree().  Also I changed the printk() to make checkpatch.pl happy.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>