[media] s5p-mfc: fix sparse error

s5p_mfc_enc.c:1178:25: error: incompatible types in conditional expression (different base types)

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>