Avoid spinning up CD on pressing eject button

Avoid spinning up CD on pressing eject button

When the CD tray door is locked and the hardware eject button is pressed, newer
kernels (2.6.38+) will send out a change event with a DISK_EJECT_REQUEST==1
property. Do not run cdrom_id and blkid in this case, as the media state and
contents does not change, and this only needlessly spins up the drive again
right before ejection.