fellow_cache: fix shutdown order - async before lru

src/fellow_cache.c

@@ -5519,13 +5519,12 @@ fellow_cache_fini(struct fellow_cache **fcp)
 		buddy_wait_kick(fc->membuddy);
 		(void) usleep(10*1000);
 	}
+	fellow_cache_async_fini(fc);
 	fellow_cache_lrus_fini(fc->lrus);
 
 	assert(VRBT_EMPTY(&fc->fdb_head));
 	AZ(*fc->g_mem_obj);
 
-	fellow_cache_async_fini(fc);
-
 	AZ(pthread_mutex_destroy(&fc->fdb_mtx));
 
 	FREE_OBJ(fc);