Buildified the world again.

bzl files were pretty off.

Change-Id: Ief87d7c0a08c6706c8c6c573afef95a6d51968e7
diff --git a/tools/build_rules/empty_main.bzl b/tools/build_rules/empty_main.bzl
index dbe9120..3305e1a 100644
--- a/tools/build_rules/empty_main.bzl
+++ b/tools/build_rules/empty_main.bzl
@@ -1,6 +1,7 @@
-'''Returns a select which is either srcs or an empty main function.'''
+"""Returns a select which is either srcs or an empty main function."""
+
 def empty_main_if_asan(srcs):
-  return select({
-    '//tools:has_asan': [ '//tools/cpp:empty_main' ],
-    '//conditions:default': srcs,
-  })
+    return select({
+        "//tools:has_asan": ["//tools/cpp:empty_main"],
+        "//conditions:default": srcs,
+    })