nft: fix leak of iterators

index c18999b..0ded02d 100644
@@ -1112,6 +1112,7 @@ next:
 		c = nft_chain_list_iter_next(iter);
 	}
 
+        nft_chain_list_iter_destroy(iter);
 	nft_chain_list_free(list);
 
 	return 1;

@@ -1200,6 +1201,7 @@ next:
 		r = nft_rule_list_iter_next(iter);
 	}
 
+        nft_chain_list_iter_destroy(list);
 	nft_rule_list_free(list);
 
 	/* the core expects 1 for success and 0 for error */

@@ -1278,6 +1280,7 @@ next:
 	}
 
 err:
+        nft_chain_list_iter_destroy(iter);
 	nft_chain_list_free(list);
 
 	/* the core expects 1 for success and 0 for error */

@@ -1391,6 +1394,7 @@ next:
 	}
 
 err:
+        nft_chain_list_iter_destroy(iter);
 	nft_chain_list_free(list);
 
 	/* chain not found */