libata: remove unused ata_sas_port_async_resume() stub

Commit bc6e7c4b "libata, libsas: kill pm_result and related cleanup"
renamed ata_sas_port_async_resume() to ata_sas_port_resume(), but missed
a CONFIG_PM=n stub conversion.  Randy fixed that up in commit
a5a65699 "libata.h: add stub for ata_sas_port_resume", but missed
the deletion of the now unused ata_sas_port_async_resume() routine.

Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NTejun Heo <tj@kernel.org>

include/linux/libata.h

@@ -1145,9 +1145,6 @@ extern void ata_sas_port_resume(struct ata_port *ap);
 static inline void ata_sas_port_suspend(struct ata_port *ap)
 {
 }
-static inline void ata_sas_port_async_resume(struct ata_port *ap)
-{
-}
 static inline void ata_sas_port_resume(struct ata_port *ap)
 {
 }