device: fixes for socket holds and leaking aio data

The aio structures need to be finalized, and the sockets should
be held until the device is totally finalized to prevent any
possible use after free.

src/core/device.c

@@ -51,6 +51,11 @@ device_fini(void *arg)
 	for (int i = 0; i < d->num_paths; i++) {
 		nni_aio_stop(&d->paths[i].aio);
 	}
+	for (int i = 0; i < d->num_paths; i++) {
+		nni_aio_fini(&d->paths[i].aio);
+	}
+	nni_sock_rele(d->paths[0].src);
+	nni_sock_rele(d->paths[0].dst);
 	NNI_FREE_STRUCT(d);
 }
 
@@ -97,8 +102,6 @@ device_cb(void *arg)
 				nni_aio_finish_error(d->user, d->rv);
 				d->user = NULL;
 			}
-			nni_sock_rele(d->paths[0].src);
-			nni_sock_rele(d->paths[0].dst);
 
 			nni_reap(&device_reap, d);
 		}