USB: xhci: Fix error path when configuring endpoints.

If we fail to queue an evaluate context command or a configure endpoint
command to the command ring in xhci_configure_endpoint(), we need to
remove the xhci_command structure from the device's command list before
returning.  If the command is left on the command list, it will sit there
indefinitely, blocking commands submitted after this fails.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>