net/mlx5: DR, Fix dumping of legacy modify_hdr in debug dump

The steering dump parser expects to see 0 as rewrite num of actions
in case pattern/args aren't supported - parsing of legacy modify header
is based on this assumption.
Fix this to align to parser's expectation.
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/steering/dr_dbg.c

@@ -153,14 +153,16 @@ dr_dump_rule_action_mem(struct seq_file *file, const u64 rule_id,
 			   DR_DUMP_REC_TYPE_ACTION_MODIFY_HDR, action_id,
 			   rule_id, action->rewrite->index,
 			   action->rewrite->single_action_opt,
-			   action->rewrite->num_of_actions,
+			   ptrn_arg ? action->rewrite->num_of_actions : 0,
 			   ptrn_arg ? ptrn->index : 0,
 			   ptrn_arg ? mlx5dr_arg_get_obj_id(arg) : 0);
 
+		if (ptrn_arg) {
 			for (i = 0; i < action->rewrite->num_of_actions; i++) {
 				seq_printf(file, ",0x%016llx",
 					   be64_to_cpu(((__be64 *)rewrite_data)[i]));
 			}
+		}
 
 		seq_puts(file, "\n");
 		break;