Remove patch for inaccessible disks; add remark in README file

The original patch for better support for inaccessible disks based
on problems with usb sticks. But this option 'inaccessible' is only 
usable, if hard disks can not be accessed by the BIOS, but always 
by linux. This option is not sensible for usb sticks, which will
always bring failures if they are named in the lilo.conf.
