client_migrate_info was merged badly, placing it between the command
and the documentation for another command. In addition it did not
respect the general rule of hmp-commands.hx, of having command
definition before the documentation.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>