drm/ttm: Fix coding style in ttm_tt_swapout()

Add missing {} braces.
Signed-off-by: NTom St Denis <tom.stdenis@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/ttm/ttm_tt.c

@@ -352,8 +352,9 @@ int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage)
 			pr_err("Failed allocating swap storage\n");
 			return PTR_ERR(swap_storage);
 		}
-	} else
+	} else {
 		swap_storage = persistent_swap_storage;
+	}
 
 	swap_space = swap_storage->f_mapping;