kconfig: remove redundant check in expr_join_or()

The check for 'sym1 == sym2' is redundant here because it has already
been done a few lines above:

    if (sym1 != sym2)
            return NULL;
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/expr.c

@@ -476,7 +476,7 @@ static struct expr *expr_join_or(struct expr *e1, struct expr *e2)
 			return expr_alloc_comp(E_UNEQUAL, sym1, &symbol_yes);
 		}
 	}
-	if (sym1->type == S_BOOLEAN && sym1 == sym2) {
+	if (sym1->type == S_BOOLEAN) {
 		if ((e1->type == E_NOT && e1->left.expr->type == E_SYMBOL && e2->type == E_SYMBOL) ||
 		    (e2->type == E_NOT && e2->left.expr->type == E_SYMBOL && e1->type == E_SYMBOL))
 			return expr_alloc_symbol(&symbol_yes);