Simplified previous fix.

src/libknot/dnssec/zone-nsec.c

@@ -942,11 +942,7 @@ int knot_zone_connect_nsec_nodes(knot_zone_contents_t *zone)
 			break;
 		}
 
-		if (nsec3_node != NULL) {
-			node->nsec3_node = nsec3_node;
-		} else {
-			node->nsec3_node = NULL;
-		}
+		node->nsec3_node = nsec3_node;
 
 		knot_dname_free(&nsec3_name);
 		hattrie_iter_next(it);