[media] v4l: omap_vout: Don't free buffers if they haven't been allocated

The VRFB buffers are freed when the device is closed even if they
haven't been allocated by a call to VIDIOC_REQBUFS, resulting in a
crash. Fix it by not trying to free buffers that are not allocated.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/omap/omap_vout_vrfb.c

@@ -79,10 +79,12 @@ void omap_vout_free_vrfb_buffers(struct omap_vout_device *vout)
 	int j;
 
 	for (j = 0; j < VRFB_NUM_BUFS; j++) {
-		omap_vout_free_buffer(vout->smsshado_virt_addr[j],
-				vout->smsshado_size);
-		vout->smsshado_virt_addr[j] = 0;
-		vout->smsshado_phy_addr[j] = 0;
+		if (vout->smsshado_virt_addr[j]) {
+			omap_vout_free_buffer(vout->smsshado_virt_addr[j],
+					      vout->smsshado_size);
+			vout->smsshado_virt_addr[j] = 0;
+			vout->smsshado_phy_addr[j] = 0;
+		}
 	}
 }