drm/ttm: Fix a memory leak

Free the memory on failure.
Also no need to re-alloc memory on retry.

Signed-off-by: xinhui pan <xinhui.pan@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219042547.44855-1-xinhui.pan@amd.com
Reviewed-by: Christian König <christian.koenig@amd.com>
CC: stable@vger.kernel.org # 5.11
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/ttm/ttm_bo.c

@@ -959,8 +959,10 @@ static int ttm_bo_bounce_temp_buffer(struct ttm_buffer_object *bo,
 		return ret;
 	/* move to the bounce domain */
 	ret = ttm_bo_handle_move_mem(bo, &hop_mem, false, ctx, NULL);
-	if (ret)
+	if (ret) {
+		ttm_resource_free(bo, &hop_mem);
 		return ret;
+	}
 	return 0;
 }
 
@@ -991,18 +993,19 @@ static int ttm_bo_move_buffer(struct ttm_buffer_object *bo,
 	 * stop and the driver will be called to make
 	 * the second hop.
 	 */
-bounce:
 	ret = ttm_bo_mem_space(bo, placement, &mem, ctx);
 	if (ret)
 		return ret;
+bounce:
 	ret = ttm_bo_handle_move_mem(bo, &mem, false, ctx, &hop);
 	if (ret == -EMULTIHOP) {
 		ret = ttm_bo_bounce_temp_buffer(bo, &mem, ctx, &hop);
 		if (ret)
-			return ret;
+			goto out;
 		/* try and move to final place now. */
 		goto bounce;
 	}
+out:
 	if (ret)
 		ttm_resource_free(bo, &mem);
 	return ret;