media: verisilicon: Stop direct calls to queue num_buffers field

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.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
CC: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>

drivers/media/platform/verisilicon/hantro_postproc.c

@@ -195,7 +195,7 @@ int hantro_postproc_alloc(struct hantro_ctx *ctx)
 	struct hantro_dev *vpu = ctx->dev;
 	struct v4l2_m2m_ctx *m2m_ctx = ctx->fh.m2m_ctx;
 	struct vb2_queue *cap_queue = &m2m_ctx->cap_q_ctx.q;
-	unsigned int num_buffers = cap_queue->num_buffers;
+	unsigned int num_buffers = vb2_get_num_buffers(cap_queue);
 	struct v4l2_pix_format_mplane pix_mp;
 	const struct hantro_fmt *fmt;
 	unsigned int i, buf_size;