Fix dead store warning.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153988 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndexDiagnostic.cpp b/tools/libclang/CIndexDiagnostic.cpp
index 67aa770..d8a2b05 100644
--- a/tools/libclang/CIndexDiagnostic.cpp
+++ b/tools/libclang/CIndexDiagnostic.cpp
@@ -336,7 +336,8 @@
         }
       }
     }
-    
+
+    (void) NeedComma; // Silence dead store warning.
     if (!NeedBracket)
       Out << "]";
   }