Switch to a more idiomatic way of silencing unused variable warnings in

release builds. Silences clang's -Wself-assign.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150942 91177308-0d34-0410-b5e6-96231b3b80d8

examples/ParallelJIT/ParallelJIT.cpp

@@ -209,7 +209,8 @@ private:
     waitFor = 0;
 
     int result = pthread_cond_broadcast( &condition );
-    assert(result == 0); result=result;
+    (void)result;
+    assert(result == 0);
   }
 
   size_t n;