kconfig: remove expr_list_for_each_sym() macro

All users of this macro have been converted. Remove it.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/expr.h

@@ -43,9 +43,6 @@ struct expr {
 #define EXPR_AND(dep1, dep2)	(((dep1)<(dep2))?(dep1):(dep2))
 #define EXPR_NOT(dep)		(2-(dep))
 
-#define expr_list_for_each_sym(l, e, s) \
-	for (e = (l); e && (s = e->right.sym); e = e->left.expr)
-
 struct expr_value {
 	struct expr *expr;
 	tristate tri;