If REQ_DRIVE_* request fails ide_end_drive_cmd() should be called
for it not ->end_request().  This was broken by 2.6.5, fix it.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@elka.pw.edu.pl>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>