media: media/saa7164: fix saa7164_encoder_register() memory leak bugs

Add a fix for the memory leak bugs that can occur when the
saa7164_encoder_register() function fails.
The function allocates memory without explicitly freeing
it when errors occur.
Add a better error handling that deallocate the unused buffers before the
function exits during a fail.

Signed-off-by: Daniel Niv <danielniv3@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>