* remote-udi.c (udi_files_info): If prog_name is NULL, just skip

	* remote-udi.c (udi_files_info): If prog_name is NULL, just skip
	printing the program, rather than passing NULL to printf.
	(udi_detach): Set udi_session_id to -1 so that udi_close doesn't
	try to call UDIDisconnect again.  Print better message.
	(udi_kill): Just call UDIDisconnect ourselves, rather than doing
	it via udi_close.
	(udi_open): Unpush UDI target after target_preopen, now that
	udi_kill doesn't pop the target.
	(udi_create_inferior): If udi_session_id is negative, open a new
	TIP rather than giving an error.