[MC] Remove dead code.

Author: kosarev

llvm/lib/MC/MCContext.cpp

@@ -575,9 +575,6 @@ MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
                                        const MCSymbolELF *GroupSym,
                                        bool IsComdat, unsigned UniqueID,
                                        const MCSymbolELF *LinkedToSym) {
-  StringRef Group = "";
-  if (GroupSym)
-    Group = GroupSym->getName();
   assert(!(LinkedToSym && LinkedToSym->getName().empty()));
 
   // Sections are differentiated by the quadruple (section_name, group_name,