media: exynos4-is: remove redundant check on type

The check to see if type is V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE is redundant
as this has been already checked at the start of the function and if
it's not that value then -ENOSYS is returned. Hence the sprintf can be
replaced by a simpler string copy.

Detected by CoverityScan, CID#1309450 ("Logically dead code")

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>