target: Minor cleanups to core_tmr_drain_tmr_list

This patch adds a handful minor cleanups to core_tmr_drain_tmr_list() that
remove an unnecessary NULL check, use list_for_each_entry_safe() instead of
list_entry(), and makes the drain_tmr_list walk use *tmr_p instead of
directly referencing the passed *tmr function parameter.
Signed-off-by: Joern Engel <joern@logfs.org>
Cc: Joern Engel <joern@logfs.org>
Reviewed-by: Roland Dreier <roland@purestorage.com>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_tmr.c

@@ -118,7 +118,7 @@ static void core_tmr_drain_tmr_list(
 		/*
 		 * Allow the received TMR to return with FUNCTION_COMPLETE.
 		 */
-		if (tmr && (tmr_p == tmr))
+		if (tmr_p == tmr)
 			continue;
 
 		cmd = tmr_p->task_cmd;
@@ -151,15 +151,14 @@ static void core_tmr_drain_tmr_list(
 	}
 	spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
 
-	while (!list_empty(&drain_tmr_list)) {
-		tmr = list_entry(drain_tmr_list.next, struct se_tmr_req, tmr_list);
-		list_del(&tmr->tmr_list);
-		cmd = tmr->task_cmd;
+	list_for_each_entry_safe(tmr_p, tmr_pp, &drain_tmr_list, tmr_list) {
+		list_del(&tmr_p->tmr_list);
+		cmd = tmr_p->task_cmd;
 
 		pr_debug("LUN_RESET: %s releasing TMR %p Function: 0x%02x,"
 			" Response: 0x%02x, t_state: %d\n",
-			(preempt_and_abort_list) ? "Preempt" : "", tmr,
-			tmr->function, tmr->response, cmd->t_state);
+			(preempt_and_abort_list) ? "Preempt" : "", tmr_p,
+			tmr_p->function, tmr_p->response, cmd->t_state);
 
 		transport_cmd_finish_abort(cmd, 1);
 	}