media: amphion: Use vb2_get_buffer() instead of directly access to buffers array

Use vb2_get_buffer() instead of direct access to the vb2_queue bufs array.
This allows us to change the type of the bufs in the future.
After each call to vb2_get_buffer() we need to be sure that we get
a valid pointer so check the return value of all of them.

Signed-off-by: Benjamin Gaignard <[e-mail]>
Reviewed-by: Andrzej Pietrasiewicz <[e-mail]>
CC: Ming Qian <[e-mail]>
CC: Zhou Peng <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/platform/amphion/vpu_dbg.c

···
 
 	vq = v4l2_m2m_get_src_vq(inst->fh.m2m_ctx);
 	for (i = 0; i < vq->num_buffers; i++) {
-		struct vb2_buffer *vb = vq->bufs[i];
-		struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+		struct vb2_buffer *vb;
+		struct vb2_v4l2_buffer *vbuf;
+
+		vb = vb2_get_buffer(vq, i);
+		if (!vb)
+			continue;
 
 		if (vb->state == VB2_BUF_STATE_DEQUEUED)
 			continue;
+
+		vbuf = to_vb2_v4l2_buffer(vb);
+
 		num = scnprintf(str, sizeof(str),
 				"output [%2d] state = %10s, %8s\n",
 				i, vb2_stat_name[vb->state],
···
 
 	vq = v4l2_m2m_get_dst_vq(inst->fh.m2m_ctx);
 	for (i = 0; i < vq->num_buffers; i++) {
-		struct vb2_buffer *vb = vq->bufs[i];
-		struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+		struct vb2_buffer *vb;
+		struct vb2_v4l2_buffer *vbuf;
+
+		vb = vb2_get_buffer(vq, i);
+		if (!vb)
+			continue;
 
 		if (vb->state == VB2_BUF_STATE_DEQUEUED)
 			continue;
+
+		vbuf = to_vb2_v4l2_buffer(vb);
+
 		num = scnprintf(str, sizeof(str),
 				"capture[%2d] state = %10s, %8s\n",
 				i, vb2_stat_name[vb->state],