- rename llist_add_to.c to llist.c

- move llist_add_to_end() from ifupdown.c to libbb/llist.c

libbb/llist.c

@@ -0,0 +1,43 @@
+#include <stdlib.h>
+#include <string.h>
+#include "unarchive.h"
+#include "libbb.h"
+
+#ifdef L_llist_add_to
+extern llist_t *llist_add_to(llist_t *old_head, char *new_item)
+{
+	llist_t *new_head;
+
+	new_head = xmalloc(sizeof(llist_t));
+	new_head->data = new_item;
+	new_head->link = old_head;
+
+	return (new_head);
+}
+#endif
+
+#ifdef L_llist_add_to_end
+extern llist_t *llist_add_to_end(llist_t *list_head, char *data)
+{
+	llist_t *new_item, *tmp, *prev;
+
+	new_item = xmalloc(sizeof(llist_t));
+	new_item->data = data;
+	new_item->link = NULL;
+
+	prev = NULL;
+	tmp = list_head;
+	while (tmp) {
+		prev = tmp;
+		tmp = tmp->link;
+	}
+	if (prev) {
+		prev->link = new_item;
+	} else {
+		list_head = new_item;
+	}
+
+	return (list_head);
+}
+#endif
+