Fix cpplint whitespace/parens issues

Change-Id: Ifc678d59a8bed24ffddde5a0e543620b17b0aba9
diff --git a/runtime/atomic_integer.h b/runtime/atomic_integer.h
index 6711722..05024b4 100644
--- a/runtime/atomic_integer.h
+++ b/runtime/atomic_integer.h
@@ -34,7 +34,7 @@
     return *this;
   }
 
-  operator int32_t () const {
+  operator int32_t() const {
     return value_;
   }