perfetto: fix typo in bazel file

Change-Id: Ia95f3e00b1d4eef8484243554e17d220be85db38
diff --git a/BUILD.extras b/BUILD.extras
index 1139c44..22e47a3 100644
--- a/BUILD.extras
+++ b/BUILD.extras
@@ -13,7 +13,7 @@
 )
 
 py_binary(
-    name = "gen_merged_sql_metrics_py"
+    name = "gen_merged_sql_metrics_py",
     srcs = [
       "tools/gen_merged_sql_metrics"
     ]