The four checksum tests are similar, only one line is different. So
a for-loop can be used to simplify these tests.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 .../testing/selftests/net/mptcp/mptcp_join.sh | 40 +++++--------------
 1 file changed, 10 insertions(+), 30 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index a4012e09728d..df9bc6e2ed09 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -3029,37 +3029,17 @@ syncookies_tests()
 
 checksum_tests()
 {
-	# checksum test 0 0
-	if reset_with_checksum 0 0; then
-		pm_nl_set_limits $ns1 0 1
-		pm_nl_set_limits $ns2 0 1
-		run_tests $ns1 $ns2 10.0.1.1
-		chk_join_nr 0 0 0
-	fi
+	local enable
 
-	# checksum test 1 1
-	if reset_with_checksum 1 1; then
-		pm_nl_set_limits $ns1 0 1
-		pm_nl_set_limits $ns2 0 1
-		run_tests $ns1 $ns2 10.0.1.1
-		chk_join_nr 0 0 0
-	fi
-
-	# checksum test 0 1
-	if reset_with_checksum 0 1; then
-		pm_nl_set_limits $ns1 0 1
-		pm_nl_set_limits $ns2 0 1
-		run_tests $ns1 $ns2 10.0.1.1
-		chk_join_nr 0 0 0
-	fi
-
-	# checksum test 1 0
-	if reset_with_checksum 1 0; then
-		pm_nl_set_limits $ns1 0 1
-		pm_nl_set_limits $ns2 0 1
-		run_tests $ns1 $ns2 10.0.1.1
-		chk_join_nr 0 0 0
-	fi
+	for enable in "0 0" "1 1" "0 1" "1 0"; do
+		# checksum test 0 0, 1 1, 0 1, 1 0
+		if reset_with_checksum $enable; then
+			pm_nl_set_limits $ns1 0 1
+			pm_nl_set_limits $ns2 0 1
+			run_tests $ns1 $ns2 10.0.1.1
+			chk_join_nr 0 0 0
+		fi
+	done
 }
 
 deny_join_id0_tests()
-- 
2.35.3