*: use llist_pop for traverse-and-free list operation

function                                             old     new   delta
append_file_list_to_list                             109     111      +2
udhcpc_main                                         2414    2413      -1
run_parts_main                                       325     324      -1
od_main                                             2324    2323      -1
getopt_main                                          709     707      -2
env_main                                             253     251      -2
sed_main                                             659     656      -3
ps_main                                              522     519      -3
traceroute_main                                     3960    3954      -6
sort_main                                            844     838      -6
diff_main                                            866     858      -8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/10 up/down: 2/-33)            Total: -31 bytes

diff --git a/editors/diff.c b/editors/diff.c
index 4e51f6f..26f3527 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -1289,14 +1289,9 @@
 	while (L_arg) {
 		if (label1 && label2)
 			bb_show_usage();
-		if (!label1)
-			label1 = L_arg->data;
-		else { /* then label2 is NULL */
+		if (label1) /* then label2 is NULL */
 			label2 = label1;
-			label1 = L_arg->data;
-		}
-		/* we leak L_arg here... */
-		L_arg = L_arg->link;
+		label1 = llist_pop(&L_arg);
 	}
 
 	/*
diff --git a/editors/sed.c b/editors/sed.c
index 817840d..bf01fc6 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -1267,21 +1267,17 @@
 	if (opt & 0x2) G.regex_type |= REG_EXTENDED; // -r
 	//if (opt & 0x4) G.be_quiet++; // -n
 	while (opt_e) { // -e
-		add_cmd_block(opt_e->data);
-		opt_e = opt_e->link;
-		/* we leak opt_e here... */
+		add_cmd_block(llist_pop(&opt_e));
 	}
 	while (opt_f) { // -f
 		char *line;
 		FILE *cmdfile;
-		cmdfile = xfopen(opt_f->data, "r");
+		cmdfile = xfopen(llist_pop(&opt_f), "r");
 		while ((line = xmalloc_fgetline(cmdfile)) != NULL) {
 			add_cmd(line);
 			free(line);
 		}
 		fclose(cmdfile);
-		opt_f = opt_f->link;
-		/* we leak opt_f here... */
 	}
 	/* if we didn't get a pattern from -e or -f, use argv[0] */
 	if (!(opt & 0x18)) {