migration: Remove unused socket_send_channel_create_sync

socket_send_channel_create_sync only use was removed by
  d0edb8a173 ("migration: Create the postcopy preempt channel asynchronously")

Remove it.

Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240919134626.166183-5-dave@treblig.org
Signed-off-by: Peter Xu <peterx@redhat.com>

migration/socket.c

@@ -42,24 +42,6 @@ void socket_send_channel_create(QIOTaskFunc f, void *data)
                                      f, data, NULL, NULL);
 }
 
-QIOChannel *socket_send_channel_create_sync(Error **errp)
-{
-    QIOChannelSocket *sioc = qio_channel_socket_new();
-
-    if (!outgoing_args.saddr) {
-        object_unref(OBJECT(sioc));
-        error_setg(errp, "Initial sock address not set!");
-        return NULL;
-    }
-
-    if (qio_channel_socket_connect_sync(sioc, outgoing_args.saddr, errp) < 0) {
-        object_unref(OBJECT(sioc));
-        return NULL;
-    }
-
-    return QIO_CHANNEL(sioc);
-}
-
 struct SocketConnectData {
     MigrationState *s;
     char *hostname;

migration/socket.h

@@ -22,7 +22,6 @@
 #include "qemu/sockets.h"
 
 void socket_send_channel_create(QIOTaskFunc f, void *data);
-QIOChannel *socket_send_channel_create_sync(Error **errp);
 
 void socket_start_incoming_migration(SocketAddress *saddr, Error **errp);