Fix syntax error

Change-Id: I20ede06a825414d7e68b8a230473c84c19490861
diff --git a/BUILD.extras b/BUILD.extras
index eb4eddf..53392a7 100644
--- a/BUILD.extras
+++ b/BUILD.extras
@@ -143,6 +143,6 @@
         ":protobuf_noop",
         ":protobuf_descriptor_pb2_noop",
         ":pyglib_noop",
-    ]
+    ],
     visibility = PERFETTO_CONFIG.public_visibility,
 )