I am about to change llvm::MemoryBuffer::getFile take take a Twine. Change
clang first so that the build still works.

llvm-svn: 193428
diff --git a/clang/lib/Format/Format.cpp b/clang/lib/Format/Format.cpp
index fd84454..54d0b1f 100644
--- a/clang/lib/Format/Format.cpp
+++ b/clang/lib/Format/Format.cpp
@@ -1428,7 +1428,8 @@
 
     if (IsFile) {
       OwningPtr<llvm::MemoryBuffer> Text;
-      if (llvm::error_code ec = llvm::MemoryBuffer::getFile(ConfigFile, Text)) {
+      if (llvm::error_code ec =
+              llvm::MemoryBuffer::getFile(ConfigFile.c_str(), Text)) {
         llvm::errs() << ec.message() << "\n";
         continue;
       }