target: Add SCF_SCSI_TMR_CDB usage and drop se_tmr_req_cache

Change the test for if a cmd is a tmr request to checking if
SCF_SCSI_TMR_CDB (a new flag) is set in cmd->se_cmd_flags.

Also remove se_tmr_req_cache usage in favor of kzalloc usage,
and make core_tmr_alloc_req() return int + setup se_cmd->se_tmr_req
directly and fix up various fabric module usages

Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index c47ff7f..7cfbcb0 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -187,7 +187,7 @@
 	 * pointer.  These will be released directly in tcm_loop_device_reset()
 	 * with transport_generic_free_cmd().
 	 */
-	if (se_cmd->se_tmr_req)
+	if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
 		return 0;
 	/*
 	 * Release the struct se_cmd, which will make a callback to release
@@ -324,7 +324,7 @@
 	struct tcm_loop_nexus *tl_nexus;
 	struct tcm_loop_tmr *tl_tmr = NULL;
 	struct tcm_loop_tpg *tl_tpg;
-	int ret = FAILED;
+	int ret = FAILED, rc;
 	/*
 	 * Locate the tcm_loop_hba_t pointer
 	 */
@@ -365,12 +365,9 @@
 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
 				DMA_NONE, MSG_SIMPLE_TAG,
 				&tl_cmd->tl_sense_buf[0]);
-	/*
-	 * Allocate the LUN_RESET TMR
-	 */
-	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd, tl_tmr,
-						TMR_LUN_RESET, GFP_KERNEL);
-	if (IS_ERR(se_cmd->se_tmr_req))
+
+	rc = core_tmr_alloc_req(se_cmd, tl_tmr, TMR_LUN_RESET, GFP_KERNEL);
+	if (rc < 0)
 		goto release;
 	/*
 	 * Locate the underlying TCM struct se_lun from sc->device->lun