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. If 'min_buffers_needed' is set remove useless checks in queue setup functions. Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> CC: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>