libclang: remove unneeded const_cast


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174283 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/libclang/CIndexUSRs.cpp b/tools/libclang/CIndexUSRs.cpp
index 7b73239..01b0053 100644
--- a/tools/libclang/CIndexUSRs.cpp
+++ b/tools/libclang/CIndexUSRs.cpp
@@ -810,7 +810,7 @@
     return true;
 
   USRGenerator UG(&D->getASTContext(), &Buf);
-  UG->Visit(const_cast<Decl*>(D));
+  UG->Visit(D);
 
   if (UG->ignoreResults())
     return true;