spice: fix segfault in qemu_spice_create_update, ui_info tweaks.

# gpg: Signature made Thu Jun 11 08:48:49 2015 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/spice/tags/pull-spice-20150611-1:
  spice: ui_info tweaks
  spice-display: fix segfault in qemu_spice_create_update

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