iscsi-target: Fix iscsit_sequence_cmd reject handling for iser

This patch moves ISCSI_OP_REJECT failures into iscsit_sequence_cmd()
in order to avoid external iscsit_reject_cmd() reject usage for all
PDU types.

It also updates PDU specific handlers for traditional iscsi-target
code to not reset the session after posting a ISCSI_OP_REJECT during
setup.

(v2: Fix CMDSN_LOWER_THAN_EXP for ISCSI_OP_SCSI to call
     target_put_sess_cmd() after iscsit_sequence_cmd() failure)

Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: stable@vger.kernel.org  # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

include/target/iscsi/iscsi_transport.h

@@ -86,4 +86,5 @@ extern int iscsit_tmr_post_handler(struct iscsi_cmd *, struct iscsi_conn *);
  * From iscsi_target_util.c
  */
 extern struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *, gfp_t);
-extern int iscsit_sequence_cmd(struct iscsi_conn *, struct iscsi_cmd *, __be32);
+extern int iscsit_sequence_cmd(struct iscsi_conn *, struct iscsi_cmd *,
+			       unsigned char *, __be32);