Use vb2_get_num_buffers() to avoid using queue num_buffers field directly. This allows us to change how the number of buffers is computed in the future. While at it, check the return value of vb2_get_buffer(). Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com> Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> CC: Maxime Ripard <mripard@kernel.org> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>