[media] c8sectpfe: fix memory leak

We have assigned memory while requesting the firmware but if the sanity
check fails then we are not releasing the firmware.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>