V4L/DVB: V4L: vpfe_capture - free ccdc_lock when memory allocation fails

This patch fixes a bug in vpfe_probe() that doesn't call mutex_unlock() if memory
allocation for ccdc_cfg fails. See also the smatch warning report from Dan
Carpenter that shows this as an issue.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>