USB/PCI/PCMCIA: Clean up new_id and remove_id sysfs attribute routines

This patch (as1514) cleans up some places where new_id and remove_id
sysfs attributes are created and deleted.  Handling both attributes in
a single routine rather than a pair of routines makes the code
smaller.  It also prevents certain kinds of errors, like one we
currently have in the USB subsystem: The removeid attribute is often
created even when newid isn't (because the driver's no_dynamid_id flag
is set).

In the case of the PCMCIA subsystem, the newid attribute is created
but never explicitly deleted.  The patch adds a deletion routine.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 059699f..249b889 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -157,6 +157,11 @@
 	return error;
 }
 
+static void
+pcmcia_remove_newid_file(struct pcmcia_driver *drv)
+{
+	driver_remove_file(&drv->drv, &driver_attr_new_id);
+}
 
 /**
  * pcmcia_register_driver - register a PCMCIA driver with the bus core
@@ -201,6 +206,7 @@
 void pcmcia_unregister_driver(struct pcmcia_driver *driver)
 {
 	pr_debug("unregistering driver %s\n", driver->name);
+	pcmcia_remove_newid_file(driver);
 	driver_unregister(&driver->drv);
 	pcmcia_free_dynids(driver);
 }