Fix Casting

Use const_cast<> to avoid a cast-away-const error.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172563 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CXLoadedDiagnostic.cpp b/tools/libclang/CXLoadedDiagnostic.cpp
index e5b6ccc..cdf9d17 100644
--- a/tools/libclang/CXLoadedDiagnostic.cpp
+++ b/tools/libclang/CXLoadedDiagnostic.cpp
@@ -512,7 +512,7 @@
     reportInvalidFile("Corrupted file entry in source location");
     return Failure;
   }
-  Loc.file = (void*) FE;
+  Loc.file = const_cast<FileEntry *>(FE);
   Loc.line = Record[offset++];
   Loc.column = Record[offset++];
   Loc.offset = Record[offset++];