staging: gasket: sysfs: clean up state if ENOMEM removing mapping

If kcalloc() returns NULL in put_mapping(), continue to clean up state,
including dropping the reference on the struct device and free attribute
memory.
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_sysfs.c

@@ -101,13 +101,12 @@ static void put_mapping(struct gasket_sysfs_mapping *mapping)
 		files_to_remove = kcalloc(num_files_to_remove,
 					  sizeof(*files_to_remove),
 					  GFP_KERNEL);
-		if (!files_to_remove) {
-			mutex_unlock(&mapping->mutex);
-			return;
-		}
-
-		for (i = 0; i < num_files_to_remove; i++)
-			files_to_remove[i] = mapping->attributes[i].attr;
+		if (files_to_remove)
+			for (i = 0; i < num_files_to_remove; i++)
+				files_to_remove[i] =
+				    mapping->attributes[i].attr;
+		else
+			num_files_to_remove = 0;
 
 		kfree(mapping->attributes);
 		mapping->attributes = NULL;