Remove the unused but set variable se_tpg in vhost_scsi_nexus_cb() to
fix the following GCC warning when building with 'W=1':
  drivers/vhost/scsi.c:1752:26: warning: variable ‘se_tpg’ set but not used
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
 static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
                                const char *name)
 {
-       struct se_portal_group *se_tpg;
        struct vhost_scsi_nexus *tv_nexus;
 
        mutex_lock(&tpg->tv_tpg_mutex);
                pr_debug("tpg->tpg_nexus already exists\n");
                return -EEXIST;
        }
-       se_tpg = &tpg->se_tpg;
 
        tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
        if (!tv_nexus) {