Fix -Wuninitialized build by referencing the relevant ctor parameter instead of the base class member variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228554 91177308-0d34-0410-b5e6-96231b3b80d8

lib/DebugInfo/PDB/PDBSymbolLabel.cpp

@@ -16,6 +16,6 @@ using namespace llvm;
 
 PDBSymbolLabel::PDBSymbolLabel(const IPDBSession &PDBSession,
                                std::unique_ptr<IPDBRawSymbol> Symbol)
-    : PDBSymbol(Session, std::move(Symbol)) {}
+    : PDBSymbol(PDBSession, std::move(Symbol)) {}
 
 void PDBSymbolLabel::dump(llvm::raw_ostream &OS) const {}