Buildify the world

Change-Id: I41c06a3f567bc45d401386cc32d9c40cb6ed95d8
diff --git a/third_party/libevent/BUILD b/third_party/libevent/BUILD
index da05f3c..347ec0b 100644
--- a/third_party/libevent/BUILD
+++ b/third_party/libevent/BUILD
@@ -148,7 +148,7 @@
         "_EVENT_STDC_HEADERS=1",
         "_EVENT_TIME_WITH_SYS_TIME=1",
         "_EVENT_NUMERIC_VERSION=0x02001600",
-        '_EVENT_VERSION=\\"2.0.22-stable\\"',
+        "_EVENT_VERSION=\\\"2.0.22-stable\\\"",
     ] + address_size_select({
         "32": [
             "_EVENT_SIZEOF_LONG_LONG=4",