ipc-server: minor code cleanup

No logic change here, this one is mostly to please static analyzer:
 - client->fd can never be -1 (and if it could, close() a few lines below
would have needed the same check)
 - we never send permission denied error (dead code)

sway/ipc-server.c

@@ -386,9 +386,7 @@ void ipc_client_disconnect(struct ipc_client *client) {
 		return;
 	}
 
-	if (client->fd != -1) {
-		shutdown(client->fd, SHUT_RDWR);
-	}
+	shutdown(client->fd, SHUT_RDWR);
 
 	wlr_log(L_INFO, "IPC Client %d disconnected", client->fd);
 	wl_event_source_remove(client->event_source);
@@ -468,8 +466,6 @@ void ipc_client_handle_command(struct ipc_client *client) {
 	}
 	buf[client->payload_length] = '\0';
 
-	const char *error_denied = "{ \"success\": false, \"error\": \"Permission denied\" }";
-
 	switch (client->current_command) {
 	case IPC_COMMAND:
 	{
@@ -650,9 +646,6 @@ void ipc_client_handle_command(struct ipc_client *client) {
 		goto exit_cleanup;
 	}
 
-	ipc_send_reply(client, error_denied, (uint32_t)strlen(error_denied));
-	wlr_log(L_DEBUG, "Denied IPC client access to %i", client->current_command);
-
 exit_cleanup:
 	client->payload_length = 0;
 	free(buf);