caif: fix memory leak in cfctrl_linkup_request()

When linktype is unknown or kzalloc failed in cfctrl_linkup_request(),
pkt is not released. Add release process to error path.

Fixes: b482cd2 ("net-caif: add CAIF core protocol stack")
Fixes: 8d545c8 ("caif: Disconnect without waiting for response")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230104065146.1153009-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/caif/cfctrl.c

@@ -269,11 +269,15 @@ int cfctrl_linkup_request(struct cflayer *layer,
 	default:
 		pr_warn("Request setup of bad link type = %d\n",
 			param->linktype);
+		cfpkt_destroy(pkt);
 		return -EINVAL;
 	}
 	req = kzalloc(sizeof(*req), GFP_KERNEL);
-	if (!req)
+	if (!req) {
+		cfpkt_destroy(pkt);
 		return -ENOMEM;
+	}
+
 	req->client_layer = user_layer;
 	req->cmd = CFCTRL_CMD_LINK_SETUP;
 	req->param = *param;