libata: move PMP SCR access failure during reset to ata_eh_reset()

If PMP fan-out reset fails and SCR isn't accessible, PMP should be
reset.  This used to be tested by sata_pmp_std_hardreset() and
communicated to EH by -ERESTART.  However, this logic is generic and
doesn't really have much to do with specific hardreset implementation.

This patch moves SCR access failure detection logic to ata_eh_reset()
where it belongs.  As this makes sata_pmp_std_hardreset() identical to
sata_std_hardreset(), the function is killed and replaced with the
standard method.

Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index e00b620..2da579b 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -91,7 +91,7 @@
 	.inherits		= &sata_port_ops,
 
 	.pmp_prereset		= ata_std_prereset,
-	.pmp_hardreset		= sata_pmp_std_hardreset,
+	.pmp_hardreset		= sata_std_hardreset,
 	.pmp_postreset		= ata_std_postreset,
 	.error_handler		= sata_pmp_error_handler,
 };
@@ -6307,7 +6307,6 @@
 #endif /* CONFIG_PCI */
 
 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
-EXPORT_SYMBOL_GPL(sata_pmp_std_hardreset);
 EXPORT_SYMBOL_GPL(sata_pmp_error_handler);
 
 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);