Fix a typo pointed about by gabor.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93997 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/Basic/MacroBuilder.h

@@ -1,4 +1,4 @@
-//===--- MacroBuilder.h - CPP Macro building utilitiy -----------*- C++ -*-===//
+//===--- MacroBuilder.h - CPP Macro building utility ------------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //