eject: inform if CD-ROM drive is not ready

eject: inform if CD-ROM drive is not ready

Include file (see linux/cdrom.h lines 395 and 398) suggests ioctl() can
return CDS_NO_INFO and CDS_DRIVE_NOT_READY, which where ignored.  This
commit will tell user what is going on.

The commit will also make eject to crash in ioctl() will return
unexpected value.

Reference: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=include/linux/cdrom.h;h=dfd7f187c351440d2ffa81050e46ed2602877f73;hb=HEAD
Signed-off-by: Sami Kerola <kerolasa@iki.fi>