Merge remote-tracking branch 'remotes/awilliam/tags/vfio-update-20150428.0' into staging

VFIO updates
 - Correction to BAR overflow
 - Fix error sign
 - Reset workaround for AMD Bonaire & Hawaii GPUs

# gpg: Signature made Tue Apr 28 18:26:43 2015 BST using RSA key ID 3BB08B22
# gpg: Good signature from "Alex Williamson <alex.williamson@redhat.com>"
# gpg:                 aka "Alex Williamson <alex@shazbot.org>"
# gpg:                 aka "Alex Williamson <alwillia@redhat.com>"
# gpg:                 aka "Alex Williamson <alex.l.williamson@gmail.com>"

* remotes/awilliam/tags/vfio-update-20150428.0:
  vfio-pci: Reset workaround for AMD Bonaire and Hawaii GPUs
  vfio-pci: Fix error path sign
  vfio-pci: Further fix BAR size overflow

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