buddy_storage: Forgotten bit when moving to new ObjWaitExtend API

For the old API, a variable assignment got lost.

Ref 12db7fc5

src/buddy_storage.c

@@ -331,6 +331,7 @@ sbu_iterator(struct worker *wrk, struct objcore *oc,
 				break;
 			continue;
 		}
+		state = boc->state;
 #else
 		nl = ObjWaitExtend(wrk, oc, ol, &state);
 		if (state == BOS_FAILED) {