media: rcar_fdp1: simplify error check logic at fdp_open()

[ Upstream commit fa9f443f7c962d072d150472e2bb77de39817a9a ]

Avoid some code duplication by moving the common error path
logic at fdp_open().

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Stable-dep-of: c766c90faf93 ("media: rcar_fdp1: Fix refcount leak in probe and remove function")
Signed-off-by: Sasha Levin <sashal@kernel.org>