Comment 1 for bug 929656

I've cherry-picked the following two patches from v3.3-rc1 into Precise:

  commit 3b9783b277e66731891ab42eeaacebbdcdd6e629
  Author: Sarah Sharp <email address hidden>
  Date: Thu Dec 22 15:02:13 2011 -0800

    xhci: Remove warnings about MSI and MSI-X capabilities.

  commit 2a9227a5eeaeb3f91e3a72ceea4fa59016ca5d20
  Author: Sarah Sharp <email address hidden>
  Date: Tue Oct 25 13:55:30 2011 +0200

    xhci: Remove scary warnings about transfer issues.