etmsync Pirelli IMEI retrieval: fix poor use of printf() Bug reported by Vadim Yanitskiy <fixeria@osmocom.org>: the construct where a static-allocated string was passed to printf() without any format arguments causes newer compilers to report a security problem. Given that formatted output is not needed here, just fixed string output, change printf() to fputs(), and direct the error message to stderr while at it.

#define	ERROR_USAGE	1
#define	ERROR_TARGET	2
#define	ERROR_RVINTERF	3
#define	ERROR_UNIX	4
#define	ERROR_BUG	5
/* the following two are for fc-rfcal-tools */
#define	ERROR_RFTEST	6	/* error in the external RF test equipment */
#define	ERROR_RFFAIL	7	/* RF calibration process failure */