Format python files using yapf

Change-Id: I8b7b97efb6bfdcceef9efc533cdaa0675ab7db40
diff --git a/tools/maindex.py b/tools/maindex.py
index 735ced5..f157498 100755
--- a/tools/maindex.py
+++ b/tools/maindex.py
@@ -7,4 +7,4 @@
 import toolhelper
 
 if __name__ == '__main__':
-  sys.exit(toolhelper.run('maindex', sys.argv[1:]))
+    sys.exit(toolhelper.run('maindex', sys.argv[1:]))