libata-link: implement ata_link_abort()

Implement ata_link_abort().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 74ced08..bfa1557 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -906,6 +906,7 @@
 extern void ata_eng_timeout(struct ata_port *ap);
 
 extern void ata_port_schedule_eh(struct ata_port *ap);
+extern int ata_link_abort(struct ata_link *link);
 extern int ata_port_abort(struct ata_port *ap);
 extern int ata_port_freeze(struct ata_port *ap);