xhci: relax link check

The strict td link limit added by commit "05f43d4 xhci: limit the
number of link trbs we are willing to process" causes problems with
Windows guests. Let's raise the limit.

This change is analogous to:

  commit ab6b1105a2259c7072905887f71caa850ce63190
  Author: Gerd Hoffmann <kraxel@redhat.com>
  Date:   Tue Mar 7 09:40:18 2017 +0100

      ohci: relax link check

Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Message-id: 20170512102100.22675-1-lprosek@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
