[media] s5p-mfc: fix error path in driver probe

This patch fixes the error path in the driver probe, so in case of
any failure, the resources are not leaked.

Reported-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>