[media] mx2_camera: fix missing unlock on error in mx2_start_streaming()

Add the missing unlock on the error handle path in function
mx2_start_streaming().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/soc_camera/mx2_camera.c

@@ -864,8 +864,10 @@ static int mx2_start_streaming(struct vb2_queue *q, unsigned int count)
 
 		bytesperline = soc_mbus_bytes_per_line(icd->user_width,
 				icd->current_fmt->host_fmt);
-		if (bytesperline < 0)
+		if (bytesperline < 0) {
+			spin_unlock_irqrestore(&pcdev->lock, flags);
 			return bytesperline;
+		}
 
 		/*
 		 * I didn't manage to properly enable/disable the prp
@@ -878,8 +880,10 @@ static int mx2_start_streaming(struct vb2_queue *q, unsigned int count)
 		pcdev->discard_buffer = dma_alloc_coherent(ici->v4l2_dev.dev,
 				pcdev->discard_size, &pcdev->discard_buffer_dma,
 				GFP_KERNEL);
-		if (!pcdev->discard_buffer)
+		if (!pcdev->discard_buffer) {
+			spin_unlock_irqrestore(&pcdev->lock, flags);
 			return -ENOMEM;
+		}
 
 		pcdev->buf_discard[0].discard = true;
 		list_add_tail(&pcdev->buf_discard[0].queue,