Merge remote-tracking branch 'remotes/kraxel/tags/pull-usb-20140711-1' into staging

mtp: linux guest detection fix

# gpg: Signature made Fri 11 Jul 2014 11:32:20 BST using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"

* remotes/kraxel/tags/pull-usb-20140711-1:
  mtp: linux guest detection fix.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>