Fix typo and obviously wrong

This commit fix my careless of submitting commit.

- q_insert_head
- merge_two_list

Change-Id: I43eb51ae34171eacbf5796b0226916ab634d3739

Author: yuto0226

queue.c

@@ -66,7 +66,7 @@ bool q_insert_head(struct list_head *head, char *s)
 bool q_insert_tail(struct list_head *head, char *s)
 {
     if (!head)
-        return NULL;
+        return false;
     element_t *e = element_new(s);
     if (!e)
         return false;
@@ -279,7 +279,7 @@ void merge_two_list(struct list_head *l, struct list_head *r, bool descend)
 
     struct list_head *l_curr = l->next;
 
-    while (!r || list_empty(r)) {
+    while (r && !list_empty(r)) {
         const element_t *l_ele = list_entry(l_curr, element_t, list);
         element_t *r_ele = list_first_entry(r, element_t, list);