migration/rdma: Drop dead qemu_rdma_data_init() code for !@host_port

migration/rdma: Drop dead qemu_rdma_data_init() code for !@host_port

qemu_rdma_data_init() neglects to set an Error when it fails because
@host_port is null.  Fortunately, no caller passes null, so this is
merely a latent bug.  Drop the flawed code handling null argument.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20230928132019.2544702-23-armbru@redhat.com>