Unify variadic errors

Author: GuillaumeGomez

src/librustc_typeck/astconv.rs

@@ -1550,7 +1550,7 @@ pub fn ast_ty_to_ty<'tcx>(this: &AstConv<'tcx>,
         ast::TyParen(ref typ) => ast_ty_to_ty(this, rscope, &**typ),
         ast::TyBareFn(ref bf) => {
             if bf.decl.variadic && bf.abi != abi::C {
-                span_err!(tcx.sess, ast_ty.span, E0222,
+                span_err!(tcx.sess, ast_ty.span, E0045,
                           "variadic function must have C calling convention");
             }
             let bare_fn = ty_of_bare_fn(this, bf.unsafety, bf.abi, &*bf.decl);