libclang: remove a few const_casts


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172373 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 33811d0..7b271dc 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -4462,7 +4462,7 @@
   case Decl::CXXConversion: {
     const FunctionDecl *Def = 0;
     if (cast<FunctionDecl>(D)->getBody(Def))
-      return MakeCXCursor(const_cast<FunctionDecl *>(Def), TU);
+      return MakeCXCursor(Def, TU);
     return clang_getNullCursor();
   }