Bugfix: SGW: Pass actual cgpu_info to prune_worklog_thread instead of silently casting one from getwork_client

driver-getwork.c

@@ -87,9 +87,9 @@ void getwork_init()
 }
 
 static
-void getwork_first_client()
+void getwork_first_client(struct cgpu_info *cgpu)
 {
-	pthread_create(&prune_worklog_pth, NULL, prune_worklog_thread, getwork_clients);
+	pthread_create(&prune_worklog_pth, NULL, prune_worklog_thread, cgpu);
 }
 
 static
@@ -203,7 +203,7 @@ int handle_getwork(struct MHD_Connection *conn, bytes_t *upbuf)
 		mutex_unlock(&getwork_clients_mutex);
 		
 		if (!b)
-			getwork_first_client();
+			getwork_first_client(cgpu);
 	}
 	else
 	{