[ELF] Fix -Woverloaded-virtual

llvm-svn: 167246
diff --git a/lld/lib/ReaderWriter/ELF/WriterELF.cpp b/lld/lib/ReaderWriter/ELF/WriterELF.cpp
index 13453b7..da4cc84 100644
--- a/lld/lib/ReaderWriter/ELF/WriterELF.cpp
+++ b/lld/lib/ReaderWriter/ELF/WriterELF.cpp
@@ -131,7 +131,7 @@
 template<support::endianness target_endianness, bool is64Bits>
 class StockSectionChunk : public SectionChunk<target_endianness, is64Bits> {
 public:
-  virtual StringRef   segmentName() { return this->_segmentName; }
+  virtual StringRef segmentName() const { return this->_segmentName; }
   void                appendAtom(const DefinedAtom*);
   virtual void        write(uint8_t *filebuffer);
   const               ArrayRef<AtomInfo> atoms() const;