rc.autostart: add error reporting (#12527)
rc.autostart: add error reporting (#12527)

-Fixed bug : cd to /etc/init.d/airframes, but no cd after
-Added error report to user if value of SYS_AUTOSTART param value is incorrect
krbeverx/Firmware,krbeverx/Firmware,dagar/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,krbeverx/Firmware,dagar/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,dagar/Firmware,dagar/Firmware,PX4/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,dagar/Firmware,acfloria/Firmware,dagar/Firmware,dagar/Firmware,acfloria/Firmware