[clang][sema] instantiateOMPDeclareVariantAttr - merge repeated VariantFuncRef.get() calls. NFCI.

Fixes scan-build warning about dead initialization

Author: RKSimon

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

@@ -436,11 +436,11 @@ static void instantiateOMPDeclareVariantAttr(
     return;
 
   Expr *E = VariantFuncRef.get();
+
   // Check function/variant ref for `omp declare variant` but not for `omp
   // begin declare variant` (which use implicit attributes).
   Optional<std::pair<FunctionDecl *, Expr *>> DeclVarData =
-      S.checkOpenMPDeclareVariantFunction(S.ConvertDeclToDeclGroup(New),
-                                          VariantFuncRef.get(), TI,
+      S.checkOpenMPDeclareVariantFunction(S.ConvertDeclToDeclGroup(New), E, TI,
                                           Attr.getRange());
 
   if (!DeclVarData)