xhci: omit mem read just after allocation of trb

This has been allocated just a few lines earlier with a
zalloc(). The value is known and "|=" is a waste of memory
cycles.

Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Link: https://lore.kernel.org/r/20220217133549.27961-1-oneukum@suse.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>