Fixed parens in an assert's conditional expression

Author: mpenick

src/handler.cpp

@@ -113,7 +113,7 @@ void Handler::set_state(Handler::State next_state) {
       break;
 
     case REQUEST_STATE_READ_BEFORE_WRITE:
-      assert(next_state == REQUEST_STATE_DONE || next_state == REQUEST_STATE_RETRY_WRITE_OUTSTANDING &&
+      assert((next_state == REQUEST_STATE_DONE || next_state == REQUEST_STATE_RETRY_WRITE_OUTSTANDING) &&
              "Invalid request state after read before write");
       state_ = next_state;
       break;