Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

vhost: build fix

Fix build breakages when using older gcc.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Thu 22 Oct 2015 20:36:07 BST using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream:
  vhost-user: fix up rhel6 build

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