Most scripts print uppercase [ OK ], [ FAIL ] and [ SKIP ] as test results,
but lowercase ones are used in diag.sh, mptcp_join.sh and simult_flows.sh.
To maintain consistency with other scripts, this patch capitalizes these
lowercase [ ok ], [ fail ] and [ skip ]:

    [ ok ]   -> [ OK ]   in diag.sh, mptcp_join.sh
    [ fail ] -> [ FAIL ] in diag.sh, mptcp_join.sh, simult_flows.sh
    [ skip ] -> [ SKIP ] in diag.sh, mptcp_join.sh

Signed-off-by: Geliang Tang <geliang.tang@linux.dev>
---
 tools/testing/selftests/net/mptcp/diag.sh         | 12 ++++++------
 tools/testing/selftests/net/mptcp/mptcp_join.sh   |  6 +++---
 tools/testing/selftests/net/mptcp/simult_flows.sh |  2 +-
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/diag.sh b/tools/testing/selftests/net/mptcp/diag.sh
index 04fcb8a077c9..efef4692a4c9 100755
--- a/tools/testing/selftests/net/mptcp/diag.sh
+++ b/tools/testing/selftests/net/mptcp/diag.sh
@@ -64,15 +64,15 @@ __chk_nr()
 	printf "%-50s" "$msg"
 	if [ $nr != $expected ]; then
 		if [ $nr = "$skip" ] && ! mptcp_lib_expect_all_features; then
-			echo "[ skip ] Feature probably not supported"
+			echo "[ SKIP ] Feature probably not supported"
 			mptcp_lib_result_skip "${msg}"
 		else
-			echo "[ fail ] expected $expected found $nr"
+			echo "[ FAIL ] expected $expected found $nr"
 			mptcp_lib_result_fail "${msg}"
 			ret=$test_cnt
 		fi
 	else
-		echo "[  ok  ]"
+		echo "[ OK ]"
 		mptcp_lib_result_pass "${msg}"
 	fi
 	test_cnt=$((test_cnt+1))
@@ -113,15 +113,15 @@ wait_msk_nr()
 
 	printf "%-50s" "$msg"
 	if [ $i -ge $timeout ]; then
-		echo "[ fail ] timeout while expecting $expected max $max last $nr"
+		echo "[ FAIL ] timeout while expecting $expected max $max last $nr"
 		mptcp_lib_result_fail "${msg} # timeout"
 		ret=$test_cnt
 	elif [ $nr != $expected ]; then
-		echo "[ fail ] expected $expected found $nr"
+		echo "[ FAIL ] expected $expected found $nr"
 		mptcp_lib_result_fail "${msg} # unexpected result"
 		ret=$test_cnt
 	else
-		echo "[  ok  ]"
+		echo "[ OK ]"
 		mptcp_lib_result_pass "${msg}"
 	fi
 	test_cnt=$((test_cnt+1))
diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh
index 1ebe6e266657..0e05024f6dd8 100755
--- a/tools/testing/selftests/net/mptcp/mptcp_join.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh
@@ -220,17 +220,17 @@ print_info()
 
 print_ok()
 {
-	mptcp_lib_print_ok "[ ok ]${1:+ ${*}}"
+	mptcp_lib_print_ok "[ OK ]${1:+ ${*}}"
 }
 
 print_fail()
 {
-	mptcp_lib_print_err "[fail]${1:+ ${*}}"
+	mptcp_lib_print_err "[ FAIL ]${1:+ ${*}}"
 }
 
 print_skip()
 {
-	mptcp_lib_print_warn "[skip]${1:+ ${*}}"
+	mptcp_lib_print_warn "[ SKIP ]${1:+ ${*}}"
 }
 
 # [ $1: fail msg ]
diff --git a/tools/testing/selftests/net/mptcp/simult_flows.sh b/tools/testing/selftests/net/mptcp/simult_flows.sh
index ae8ad5d6fb9d..d54ee402ac06 100755
--- a/tools/testing/selftests/net/mptcp/simult_flows.sh
+++ b/tools/testing/selftests/net/mptcp/simult_flows.sh
@@ -194,7 +194,7 @@ do_transfer()
 		return 0
 	fi
 
-	echo " [ fail ]"
+	echo " [ FAIL ]"
 	echo "client exit code $retc, server $rets" 1>&2
 	echo -e "\nnetns ${ns3} socket stat for $port:" 1>&2
 	ip netns exec ${ns3} ss -nita 1>&2 -o "sport = :$port"
-- 
2.35.3