fixes a doxygen comment.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@170485 91177308-0d34-0410-b5e6-96231b3b80d8

tools/libclang/SimpleFormatContext.h

@@ -7,7 +7,9 @@
 //
 //===----------------------------------------------------------------------===//
 //
-/// \file This file defines a utility class for use of clang-format in libclang
+/// \file SimpleFormatContext.h
+///
+/// \brief This file defines a utility class for use of clang-format in libclang
 //
 //===----------------------------------------------------------------------===//