ACPI / PCI / hotplug: unlock in error path in acpiphp_enable_slot()

commit 2c3033a0664dfae91e1dee7fabac10f24354b958 upstream.

In acpiphp_enable_slot(), there is a missing unlock path
when error occurred.  It needs to be unlocked before returning
an error.

Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index c074b26..0e73990 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -970,8 +970,10 @@
 {
 	pci_lock_rescan_remove();
 
-	if (slot->flags & SLOT_IS_GOING_AWAY)
+	if (slot->flags & SLOT_IS_GOING_AWAY) {
+		pci_unlock_rescan_remove();
 		return -ENODEV;
+	}
 
 	/* configure all functions */
 	if (!(slot->flags & SLOT_ENABLED))