Fix bogus diagnostic format string.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@96978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/CIndex/CIndex.cpp b/tools/CIndex/CIndex.cpp
index d95aaee..df89d73 100644
--- a/tools/CIndex/CIndex.cpp
+++ b/tools/CIndex/CIndex.cpp
@@ -1103,7 +1103,7 @@
         AllArgs += *I;
     }
 
-    Diags->Report(diag::err_fe_clang) << AllArgs << ErrMsg;
+    Diags->Report(diag::err_fe_invoking) << AllArgs << ErrMsg;
   }
 
   ASTUnit *ATU = ASTUnit::LoadFromPCHFile(astTmpFile, *Diags,