ata: ahci: rpm_put port on port_stop to match rpm_get in port_start

This change balances out the final ahci_port_resume in port_start to
ensure reference counts are correct after port stop.

Signed-off-by: Samuel Morris <samorris@lexmark.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 965842a0..5038cee 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -2436,6 +2436,8 @@
 	 * re-enabling INTx.
 	 */
 	writel(1 << ap->port_no, host_mmio + HOST_IRQ_STAT);
+
+	ahci_rpm_put_port(ap);
 }
 
 void ahci_print_info(struct ata_host *host, const char *scc_s)