Add selftest for "team: avoid NETDEV_CHANGEMTU event when unregistering
slave" patch.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
---
Does Makefile look OK?

 tools/testing/selftests/net/team/Makefile     |  7 ++++++
 .../selftests/net/team/team_unregister.sh     | 24 +++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 tools/testing/selftests/net/team/Makefile
 create mode 100755 tools/testing/selftests/net/team/team_unregister.sh

diff --git a/tools/testing/selftests/net/team/Makefile b/tools/testing/selftests/net/team/Makefile
new file mode 100644
index 000000000000..aa8ef0590022
--- /dev/null
+++ b/tools/testing/selftests/net/team/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0
+
+top_srcdir = ../../../../..
+
+TEST_PROGS := team_unregister.sh
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/net/team/team_unregister.sh b/tools/testing/selftests/net/team/team_unregister.sh
new file mode 100755
index 000000000000..94dd49b0c21b
--- /dev/null
+++ b/tools/testing/selftests/net/team/team_unregister.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+
+source ../lib.sh
+
+NS_NAME="ns-"$RANDOM
+TEAM_NAME="team-"$RANDOM
+DUMMY_NAME="dummy-"$RANDOM
+
+cleanup() {
+    cleanup_ns $NS_NAME
+    ip link del $TEAM_NAME
+}
+
+trap cleanup EXIT
+ip link add name $TEAM_NAME type team
+ip link add name $DUMMY_NAME mtu 1499 master $TEAM_NAME type dummy
+ip netns add $NS_NAME
+echo "Setting $DUMMY_NAME to $NS_NAME"
+ip link set dev $DUMMY_NAME netns $NS_NAME
+echo "Deleting $DUMMY_NAME from $NS_NAME"
+ip -n $NS_NAME link del dev $DUMMY_NAME
+echo "Test completed successfully."
-- 
2.53.0