net: mvpp2: cls: Fix memory leak in mvpp2_ethtool_cls_rule_ins()

In mvpp2_ethtool_cls_rule_ins(), the ethtool_rule is allocated by
ethtool_rx_flow_rule_create(). If the subsequent conversion to flow
type fails, the function jumps to the clean_rule label.

However, the clean_rule label only frees efs, skipping the cleanup
of ethtool_rule, which leads to a memory leak.

Fix this by jumping to the clean_eth_rule label, which properly calls
ethtool_rx_flow_rule_destroy() before freeing efs.

Compile tested only. Issue found using a prototype static analysis tool
and code review.

Fixes: f4f1ba18195d ("net: mvpp2: cls: Report an error for unsupported flow types")
Signed-off-by: Zilin Guan <[e-mail]>
Reviewed-by: Maxime Chevallier <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c

···
 	efs->rule.flow_type = mvpp2_cls_ethtool_flow_to_type(info->fs.flow_type);
 	if (efs->rule.flow_type < 0) {
 		ret = efs->rule.flow_type;
-		goto clean_rule;
+		goto clean_eth_rule;
 	}
 
 	ret = mvpp2_cls_rfs_parse_rule(&efs->rule);