selftest: net: fix typo in altname test

stable inclusion
from stable-5.10.68
commit e00eae1d6b1fb8eecb1250fdcadcc97ea391cbe5
bugzilla: 182671 https://gitee.com/openeuler/kernel/issues/I4EWUH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=e00eae1d6b1fb8eecb1250fdcadcc97ea391cbe5

--------------------------------

commit 1b704b27 upstream.

If altname deletion of the short alternative name fails, the error
message printed is: "Failed to add short alternative name".
This is obviously a typo, as we are testing altname deletion.

Fix this using a proper error message.

Fixes: f95e6c9c ("selftest: net: add alternative names test")
Signed-off-by: NAndrea Claudi <aclaudi@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

tools/testing/selftests/net/altnames.sh

@@ -45,7 +45,7 @@ altnames_test()
 	check_err $? "Got unexpected long alternative name from link show JSON"
 
 	ip link property del $DUMMY_DEV altname $SHORT_NAME
-	check_err $? "Failed to add short alternative name"
+	check_err $? "Failed to delete short alternative name"
 
 	ip -j -p link show $SHORT_NAME &>/dev/null
 	check_fail $? "Unexpected success while trying to do link show with deleted short alternative name"