ide-cd: remove cdrom_end_request()

Inline cdrom_end_request() into cdrom_newpc_intr()
and ide_cd_do_request().

There should be no functional changes caused by this patch.

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