commit 1eaf35e4 upstream.

The module should fail to load.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: xhci_hcd_init() registers the PCI driver, so
 check before doing that rather than at the end of the function]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>