keep only the StringRef version of getFileOrSTDIN.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184826 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
index 99479a4..186eea9 100644
--- a/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
+++ b/tools/llvm-bcanalyzer/llvm-bcanalyzer.cpp
@@ -481,7 +481,7 @@
   OwningPtr<MemoryBuffer> MemBuf;
 
   if (error_code ec =
-        MemoryBuffer::getFileOrSTDIN(InputFilename.c_str(), MemBuf))
+        MemoryBuffer::getFileOrSTDIN(InputFilename, MemBuf))
     return Error("Error reading '" + InputFilename + "': " + ec.message());
 
   if (MemBuf->getBufferSize() & 3)