media: videobuf-dma-sg: void function return statements are not generally useful

void function videobuf_vm_close return statements are not generally useful,
so deleted the return in function videobuf_vm_close().
Signed-off-by: Nlijian <lijian@yulong.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/media/v4l2-core/videobuf-dma-sg.c

@@ -423,7 +423,6 @@ static void videobuf_vm_close(struct vm_area_struct *vma)
 		videobuf_queue_unlock(q);
 		kfree(map);
 	}
-	return;
 }
 
 /*