target: Remove the unused flag SCF_ACK_KREF

The flag SCF_ACK_KREF is only set but never tested. Hence remove
this flag.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 0b8411f..4edb183 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -2479,10 +2479,8 @@
 	 * fabric acknowledgement that requires two target_put_sess_cmd()
 	 * invocations before se_cmd descriptor release.
 	 */
-	if (ack_kref) {
+	if (ack_kref)
 		kref_get(&se_cmd->cmd_kref);
-		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
-	}
 
 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
 	if (se_sess->sess_tearing_down) {