PCI: fix hotplug get_##name return value problem

Currently, get_##name in pci_hotplug_core.c will return 0 if module
unload wins the race between unload & reading the hotplug file.  Fix
that case to return -ENODEV like it should.
Reviewed-by: NAlex Chiang <achiang@hp.com>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NYu Zhao <yu.zhao@intel.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

drivers/pci/hotplug/pci_hotplug_core.c

@@ -102,13 +102,13 @@ static int get_##name (struct hotplug_slot *slot, type *value)		\
 {									\
 	struct hotplug_slot_ops *ops = slot->ops;			\
 	int retval = 0;							\
-	if (try_module_get(ops->owner)) {				\
+	if (try_module_get(ops->owner))					\
+		return -ENODEV;						\
 	if (ops->get_##name)						\
 		retval = ops->get_##name(slot, value);			\
 	else								\
 		*value = slot->info->name;				\
 	module_put(ops->owner);						\
-	}								\
 	return retval;							\
 }