libiscsi: Unexport iscsi_eh_target_reset()

Running "git grep -nHw iscsi_eh_target_reset" shows that this function
is only called from inside the drivers/scsi/libiscsi.c source
file. Hence unexport this function.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libiscsi.c

@@ -2423,7 +2423,7 @@ static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
  *
  * This will attempt to send a warm target reset.
  */
-int iscsi_eh_target_reset(struct scsi_cmnd *sc)
+static int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 {
 	struct iscsi_cls_session *cls_session;
 	struct iscsi_session *session;
@@ -2495,7 +2495,6 @@ int iscsi_eh_target_reset(struct scsi_cmnd *sc)
 	mutex_unlock(&session->eh_mutex);
 	return rc;
 }
-EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
 
 /**
  * iscsi_eh_recover_target - reset target and possibly the session