Revert "[msf] Rename Msf to MSF."

This reverts commit 4d1557ffac41e079bcb1abbcf04f512474dcd6fe.

llvm-svn: 277194
diff --git a/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp b/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp
index 2f3ac34..a604df3 100644
--- a/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Raw/SymbolStream.cpp
@@ -11,8 +11,8 @@
 
 #include "llvm/DebugInfo/CodeView/CodeView.h"
 #include "llvm/DebugInfo/CodeView/TypeRecord.h"
-#include "llvm/DebugInfo/MSF/MappedBlockStream.h"
-#include "llvm/DebugInfo/MSF/StreamReader.h"
+#include "llvm/DebugInfo/Msf/MappedBlockStream.h"
+#include "llvm/DebugInfo/Msf/StreamReader.h"
 #include "llvm/DebugInfo/PDB/Raw/PDBFile.h"
 #include "llvm/DebugInfo/PDB/Raw/RawConstants.h"
 #include "llvm/DebugInfo/PDB/Raw/RawError.h"