media: staging: davinci: fix memory leaks and check for allocation failure

There are three error return paths that don't kfree params causing a
memory leak.  Fix this by adding an error return path that kfree's
params before returning.  Also add a check to see params failed to
be allocated.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>