selftests: mptcp: diag: unique 'in use' subtest names

It is important to have a unique (sub)test name in TAP, because some CI
environments drop tests with duplicated name.

Some 'in use' subtests from the diag selftest had the same names, e.g.:

    chk 0 msk in use after flush

Now the previous value is taken, to have different names, e.g.:

    chk 2->0 msk in use after flush

While at it, avoid repeating the full message, declare it once in the
helper.

Fixes: ce990257 ("selftests: mptcp: diag: format subtests results in TAP")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/mptcp/diag.sh

@@ -166,9 +166,13 @@ chk_msk_listen()
 chk_msk_inuse()
 {
 	local expected=$1
-	local msg="$2"
+	local msg="....chk ${2:-${expected}} msk in use"
 	local listen_nr
 
+	if [ "${expected}" -eq 0 ]; then
+		msg+=" after flush"
+	fi
+
 	listen_nr=$(ss -N "${ns}" -Ml | grep -c LISTEN)
 	expected=$((expected + listen_nr))
 
@@ -179,7 +183,7 @@ chk_msk_inuse()
 		sleep 0.1
 	done
 
-	__chk_nr get_msk_inuse $expected "$msg" 0
+	__chk_nr get_msk_inuse $expected "${msg}" 0
 }
 
 # $1: cestab nr
@@ -227,11 +231,11 @@ wait_connected $ns 10000
 chk_msk_nr 2 "after MPC handshake "
 chk_msk_remote_key_nr 2 "....chk remote_key"
 chk_msk_fallback_nr 0 "....chk no fallback"
-chk_msk_inuse 2 "....chk 2 msk in use"
+chk_msk_inuse 2
 chk_msk_cestab 2
 flush_pids
 
-chk_msk_inuse 0 "....chk 0 msk in use after flush"
+chk_msk_inuse 0 "2->0"
 chk_msk_cestab 0
 
 echo "a" | \
@@ -247,11 +251,11 @@ echo "b" | \
 				127.0.0.1 >/dev/null &
 wait_connected $ns 10001
 chk_msk_fallback_nr 1 "check fallback"
-chk_msk_inuse 1 "....chk 1 msk in use"
+chk_msk_inuse 1
 chk_msk_cestab 1
 flush_pids
 
-chk_msk_inuse 0 "....chk 0 msk in use after flush"
+chk_msk_inuse 0 "1->0"
 chk_msk_cestab 0
 
 NR_CLIENTS=100
@@ -273,11 +277,11 @@ for I in `seq 1 $NR_CLIENTS`; do
 done
 
 wait_msk_nr $((NR_CLIENTS*2)) "many msk socket present"
-chk_msk_inuse $((NR_CLIENTS*2)) "....chk many msk in use"
+chk_msk_inuse $((NR_CLIENTS*2)) "many"
 chk_msk_cestab $((NR_CLIENTS*2))
 flush_pids
 
-chk_msk_inuse 0 "....chk 0 msk in use after flush"
+chk_msk_inuse 0 "many->0"
 chk_msk_cestab 0
 
 mptcp_lib_result_print_all_tap