APMrover2: fix wrong printf format for printf

"%S" is used for wide string, but we are passing a char*. Use lowercase
in this case to remove warnings like this:

libraries/AP_InertialSensor/AP_InertialSensor.cpp: In member function
'bool AP_InertialSensor::calibrate_accel(AP_InertialSensor_UserInteract*, float&, float&)':
libraries/AP_InertialSensor/AP_InertialSensor.cpp:620:61: warning:
format '%S' expects argument of type 'wchar_t*', but argument 3 has type 'const char*' [-Wformat=]
                 "Place vehicle %S and press any key.\n", msg);
                                                             ^

APMrover2/Log.cpp

@@ -33,7 +33,7 @@ bool Rover::print_log_menu(void)
 		// Pass it the capitalised name of the log option, as defined
 		// in defines.h but without the LOG_ prefix.  It will check for
 		// the bit being set and print the name of the log option to suit.
-		#define PLOG(_s)	if (g.log_bitmask & MASK_LOG_ ## _s) cliSerial->printf(" %S", #_s)
+		#define PLOG(_s)	if (g.log_bitmask & MASK_LOG_ ## _s) cliSerial->printf(" %s", #_s)
 		PLOG(ATTITUDE_FAST);
 		PLOG(ATTITUDE_MED);
 		PLOG(GPS);