The length of mmap() can be bigger than length of vb2 buffer, so
it should be checked.
Signed-off-by: NSeung-Woo Kim <sw0312.kim@samsung.com>
Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>