ide: add ide_queue_pc_tail() helper

* Add ide_queue_pc_tail() and convert ide-{floppy,tape}.c to use it
  instead of ide*_queue_pc_tail().

* Remove no longer used ide*_queue_pc_tail().

There should be no functional changes caused by this patch.

Acked-by: Borislav Petkov <petkovbb@gmail.com>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 1bd49784..b5be236 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1136,6 +1136,7 @@
 
 void ide_queue_pc_head(ide_drive_t *, struct gendisk *, struct ide_atapi_pc *,
 		       struct request *);
+int ide_queue_pc_tail(ide_drive_t *, struct gendisk *, struct ide_atapi_pc *);
 
 ide_startstop_t ide_pc_intr(ide_drive_t *drive, struct ide_atapi_pc *pc,
 	ide_handler_t *handler, unsigned int timeout, ide_expiry_t *expiry,