ide: use ->end_request only for private device driver requests

* Move IDE{FLOPPY,TAPE}_ERROR_* defines to <linux/ide.h> and rename them
  to IDE_DRV_ERROR_*.

* Handle ->end_request special cases for floppy/tape media in ide_kill_rq().

* Call ->end_request only for private device driver requests.

There should be no functional changes caused by this patch.

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>