selftests: rtnetlink.sh: remove esp4_offload after test

JIRA: https://issues.redhat.com/browse/RHEL-115594

commit 5b32321
Author: Xiumei Mu <xmu@redhat.com>
Date:   Fri Jul 25 11:50:28 2025 +0800

    selftests: rtnetlink.sh: remove esp4_offload after test

    The esp4_offload module, loaded during IPsec offload tests, should
    be reset to its default settings after testing.
    Otherwise, leaving it enabled could unintentionally affect subsequence
    test cases by keeping offload active.

    Without this fix:
    $ lsmod | grep offload; ./rtnetlink.sh -t kci_test_ipsec_offload ; lsmod | grep offload;
    PASS: ipsec_offload
    esp4_offload           12288  0
    esp4                   32768  1 esp4_offload

    With this fix:
    $ lsmod | grep offload; ./rtnetlink.sh -t kci_test_ipsec_offload ; lsmod | grep offload;
    PASS: ipsec_offload

    Fixes: 2766a11 ("selftests: rtnetlink: add ipsec offload API test")
    Signed-off-by: Xiumei Mu <xmu@redhat.com>
    Reviewed-by: Shannon Nelson <sln@onemain.com>
    Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
    Link: https://patch.msgid.link/6d3a1d777c4de4eb0ca94ced9e77be8d48c5b12f.1753415428.git.xmu@redhat.com
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

Author: CKI Backport Bot

tools/testing/selftests/net/rtnetlink.sh

@@ -673,6 +673,11 @@ kci_test_ipsec_offload()
 	sysfsf=$sysfsd/ipsec
 	sysfsnet=/sys/bus/netdevsim/devices/netdevsim0/net/
 	probed=false
+	esp4_offload_probed_default=false
+
+	if lsmod | grep -q esp4_offload; then
+		esp4_offload_probed_default=true
+	fi
 
 	if ! mount | grep -q debugfs; then
 		mount -t debugfs none /sys/kernel/debug/ &> /dev/null
@@ -766,6 +771,7 @@ EOF
 	fi
 
 	# clean up any leftovers
+	! "$esp4_offload_probed_default" && lsmod | grep -q esp4_offload && rmmod esp4_offload
 	echo 0 > /sys/bus/netdevsim/del_device
 	$probed && rmmod netdevsim