selftests: mptcp: join: no extra msg if no counter

commit 76a2d83 upstream.

The checksum and fail counters might not be available. Then no need to
display an extra message with missing info.

While at it, fix the indentation around, which is wrong since the same
commit.

Fixes: 47867f0 ("selftests: mptcp: join: skip check if MIB counter not supported")
Cc: stable@vger.kernel.org
Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
[ Conflicts in mptcp_join.sh, because the context is different, but the
  exact same fix can still be applied on the modified lines: adding
  '[ -n "$count" ]', and fixing the indentation. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

@@ -1252,13 +1252,13 @@ chk_csum_nr()
 
 	printf "%-${nr_blank}s %s" " " "sum"
 	count=$(get_counter ${ns1} "MPTcpExtDataCsumErr")
-	if [ "$count" != "$csum_ns1" ]; then
+	if [ -n "$count" ] && [ "$count" != "$csum_ns1" ]; then
 		extra_msg="$extra_msg ns1=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 0 ]; } ||
-	   { [ "$count" -lt $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 1 ]; }; then
+	     { [ "$count" -lt $csum_ns1 ] && [ $allow_multi_errors_ns1 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns1"
 		fail_test
 		dump_stats=1
@@ -1267,13 +1267,13 @@ chk_csum_nr()
 	fi
 	echo -n " - csum  "
 	count=$(get_counter ${ns2} "MPTcpExtDataCsumErr")
-	if [ "$count" != "$csum_ns2" ]; then
+	if [ -n "$count" ] && [ "$count" != "$csum_ns2" ]; then
 		extra_msg="$extra_msg ns2=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 0 ]; } ||
-	   { [ "$count" -lt $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 1 ]; }; then
+	     { [ "$count" -lt $csum_ns2 ] && [ $allow_multi_errors_ns2 -eq 1 ]; }; then
 		echo "[fail] got $count data checksum error[s] expected $csum_ns2"
 		fail_test
 		dump_stats=1
@@ -1315,13 +1315,13 @@ chk_fail_nr()
 
 	printf "%-${nr_blank}s %s" " " "ftx"
 	count=$(get_counter ${ns_tx} "MPTcpExtMPFailTx")
-	if [ "$count" != "$fail_tx" ]; then
+	if [ -n "$count" ] && [ "$count" != "$fail_tx" ]; then
 		extra_msg="$extra_msg,tx=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != "$fail_tx" ] && [ $allow_tx_lost -eq 0 ]; } ||
-	   { [ "$count" -gt "$fail_tx" ] && [ $allow_tx_lost -eq 1 ]; }; then
+	     { [ "$count" -gt "$fail_tx" ] && [ $allow_tx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] TX expected $fail_tx"
 		fail_test
 		dump_stats=1
@@ -1331,13 +1331,13 @@ chk_fail_nr()
 
 	echo -n " - failrx"
 	count=$(get_counter ${ns_rx} "MPTcpExtMPFailRx")
-	if [ "$count" != "$fail_rx" ]; then
+	if [ -n "$count" ] && [ "$count" != "$fail_rx" ]; then
 		extra_msg="$extra_msg,rx=$count"
 	fi
 	if [ -z "$count" ]; then
 		echo -n "[skip]"
 	elif { [ "$count" != "$fail_rx" ] && [ $allow_rx_lost -eq 0 ]; } ||
-	   { [ "$count" -gt "$fail_rx" ] && [ $allow_rx_lost -eq 1 ]; }; then
+	     { [ "$count" -gt "$fail_rx" ] && [ $allow_rx_lost -eq 1 ]; }; then
 		echo "[fail] got $count MP_FAIL[s] RX expected $fail_rx"
 		fail_test
 		dump_stats=1