Fix cpplint whitespace/operators issues

Change-Id: I730bd87b476bfa36e93b42e816ef358006b69ba5
diff --git a/runtime/atomic_integer.h b/runtime/atomic_integer.h
index 05024b4..f31e166 100644
--- a/runtime/atomic_integer.h
+++ b/runtime/atomic_integer.h
@@ -58,11 +58,11 @@
     return android_atomic_and(-value, &value_);
   }
 
-  int32_t operator ++ () {
+  int32_t operator++ () {
     return android_atomic_inc(&value_) + 1;
   }
 
-  int32_t operator -- () {
+  int32_t operator-- () {
     return android_atomic_dec(&value_) - 1;
   }