Extract the main part of check_expected() in userspace_pm.sh to a new
function mptcp_lib_check_expected() in mptcp_lib.sh. It will be used
in both mptcp_john.sh and userspace_pm.sh.

check_expected_one() is moved into mptcp_lib.sh too as a sub function
of mptcp_lib_check_expected().

Signed-off-by: Geliang Tang <geliang.tang@linux.dev>
---
 .../testing/selftests/net/mptcp/mptcp_lib.sh  | 43 +++++++++++++++++++
 .../selftests/net/mptcp/userspace_pm.sh       | 41 +++---------------
 2 files changed, 48 insertions(+), 36 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index 94eed09ceedd..6ba3747ce217 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -381,3 +381,46 @@ mptcp_lib_evts_remove() {
 
 	rm -rf "${server_evts}" "${client_evts}"
 }
+
+# $@: all var names to check
+mptcp_lib_check_expected() {
+	: "${ret:?}"
+
+	# $1: var name ; $2: prev ret
+	check_expected_one() {
+		local var="${1}"
+		local exp="e_${var}"
+		local prev_ret="${2}"
+
+		if [ "${!var}" = "${!exp}" ]
+		then
+			return 0
+		fi
+
+		if [ "${prev_ret}" = "0" ]
+		then
+			ret=${KSFT_FAIL}
+		fi
+
+		printf "\tExpected value for '%s': '%s', got '%s'.\n" \
+			"${var}" "${!exp}" "${!var}"
+		return 1
+	}
+
+	local rc=0
+	local var
+
+	for var in "${@}"
+	do
+		check_expected_one "${var}" "${rc}" || rc=1
+	done
+	unset -f check_expected_one
+
+	if [ ${rc} -eq 0 ]
+	then
+		mptcp_lib_print_ok "[ OK ]"
+		return 0
+	fi
+
+	return 1
+}
diff --git a/tools/testing/selftests/net/mptcp/userspace_pm.sh b/tools/testing/selftests/net/mptcp/userspace_pm.sh
index 845400741cf2..0b4484472313 100755
--- a/tools/testing/selftests/net/mptcp/userspace_pm.sh
+++ b/tools/testing/selftests/net/mptcp/userspace_pm.sh
@@ -236,46 +236,15 @@ make_connection()
 	fi
 }
 
-# $1: var name ; $2: prev ret
-check_expected_one()
-{
-	local var="${1}"
-	local exp="e_${var}"
-	local prev_ret="${2}"
-
-	if [ "${!var}" = "${!exp}" ]
-	then
-		return 0
-	fi
-
-	if [ "${prev_ret}" = "0" ]
-	then
-		test_fail
-	fi
-
-	_printf "\tExpected value for '%s': '%s', got '%s'.\n" \
-		"${var}" "${!exp}" "${!var}"
-	return 1
-}
-
 # $@: all var names to check
 check_expected()
 {
-	local rc=0
-	local var
-
-	for var in "${@}"
-	do
-		check_expected_one "${var}" "${rc}" || rc=1
-	done
-
-	if [ ${rc} -eq 0 ]
-	then
-		test_pass
-		return 0
+	mptcp_lib_check_expected ${*}
+	if [ $? -eq 0 ]; then
+		mptcp_lib_result_pass "${TEST_NAME}"
+	else
+		test_fail
 	fi
-
-	return 1
 }
 
 verify_announce_event()
-- 
2.35.3