[media] v4l2-ioctl.c: check vfl_type in ENUM_FMT

The other format ioctls (g/s/try_fmt) all check if the passed buffer type
makes sense for the device node's vfl_type. E.g. it makes no sense for a
VBI buffer type to be passed through a video node instead of a vbi node.

But this check was missing in ENUM_FMT which can cause a problem if you
have both video and sdr device nodes.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>