Removed unused it_start and it_end

tests/main/src/intervalheap.c

@@ -8,8 +8,6 @@ struct intervalheap
     size_t count;
     int flag;
     struct intervalheap_fval *f_val;
-    struct intervalheap_iter (*it_start)(struct intervalheap *);
-    struct intervalheap_iter (*it_end)(struct intervalheap *);
     struct cmc_alloc_node *alloc;
     struct cmc_callbacks *callbacks;
 };

tests/main/src/linkedlist.c

@@ -9,8 +9,6 @@ struct linkedlist
     struct linkedlist_fval *f_val;
     struct cmc_alloc_node *alloc;
     struct cmc_callbacks *callbacks;
-    struct linkedlist_iter (*it_start)(struct linkedlist *);
-    struct linkedlist_iter (*it_end)(struct linkedlist *);
 };
 struct linkedlist_node
 {