fix fix-vhost-user-socket-permission.patch for 16.07

fix fix-vhost-user-socket-permission.patch for 16.07

Since preparation and actual creation of sockets was split to support
client/server sockets the call to fix up the sockets permissions has to
be moved until after the fd is created.
Otherwise the chmod/chown will fail with:
 EAL: vhost-user socket cannot set permissions to 0666 (Unknown error -1).
 EAL: vhost-user socket unable to set ownership to libvirt-qemu:kvm (Unknown
  error -1).

Change-Id: Ia91eda2f5b217a5a9aa6c2f5ddf2c882048e42b8
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>