xhci: don't dereference a xhci member after removing xhci

xhci: don't dereference a xhci member after removing xhci

commit f1f6d9a8b540df22b87a5bf6bc104edaade81f47 upstream.

Remove the hcd after checking for the xhci last quirks, not before.

This caused a hang on a Alpine Ridge xhci based maching which remove
the whole xhci controller when unplugging the last usb device

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>