Extract the main part of check() in pm_netlink.sh to a new function
mptcp_lib_check() in mptcp_lib.sh. And use mptcp_lib_print_ok() and
_err() in it to print test results with colors.

This helper will be used in mptcp_john.sh later.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 .../testing/selftests/net/mptcp/mptcp_lib.sh  | 27 +++++++++++++++++
 .../testing/selftests/net/mptcp/pm_netlink.sh | 29 +++++--------------
 2 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_lib.sh b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
index cbaa55ab89b1..466fde97d3f4 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_lib.sh
+++ b/tools/testing/selftests/net/mptcp/mptcp_lib.sh
@@ -300,7 +300,34 @@ mptcp_lib_wait_local_port_listen() {
 	done
 }
 
+mptcp_lib_err=$(mktemp)
+
+mptcp_lib_check()
+{
+	local cmd="$1"
+	local expected="$2"
+	local msg="$3"
+	local out=`$cmd 2>$mptcp_lib_err`
+	local cmd_ret=$?
+
+	printf "%-42s" "$msg"
+	if [ $cmd_ret -ne 0 ]; then
+		mptcp_lib_print_err "[FAIL] command execution '$cmd' stderr "
+		cat $mptcp_lib_err
+		ret=1
+		return $cmd_ret
+	elif [ "$out" = "$expected" ]; then
+		mptcp_lib_print_ok "[ OK ]"
+		return 0
+	else
+		mptcp_lib_print_err "[FAIL] expected '$expected' got '$out'"
+		ret=1
+		return 1
+	fi
+}
+
 mptcp_lib_cleanup()
 {
 	echo "cleanup"
+	rm -f $mptcp_lib_err
 }
diff --git a/tools/testing/selftests/net/mptcp/pm_netlink.sh b/tools/testing/selftests/net/mptcp/pm_netlink.sh
index fd413b4c8123..8d30d4a1db57 100755
--- a/tools/testing/selftests/net/mptcp/pm_netlink.sh
+++ b/tools/testing/selftests/net/mptcp/pm_netlink.sh
@@ -27,12 +27,10 @@ done
 sec=$(date +%s)
 rndh=$(printf %x $sec)-$(mktemp -u XXXXXX)
 ns1="ns1-$rndh"
-err=$(mktemp)
 ret=0
 
 cleanup()
 {
-	rm -f $err
 	ip netns del $ns1
 	mptcp_lib_cleanup
 }
@@ -53,26 +51,15 @@ ip netns exec $ns1 sysctl -q net.mptcp.enabled=1
 
 check()
 {
-	local cmd="$1"
-	local expected="$2"
-	local msg="$3"
-	local out=`$cmd 2>$err`
-	local cmd_ret=$?
-
-	printf "%-50s" "$msg"
-	if [ $cmd_ret -ne 0 ]; then
-		echo "[FAIL] command execution '$cmd' stderr "
-		cat $err
-		mptcp_lib_result_fail "${msg} # error ${cmd_ret}"
-		ret=1
-	elif [ "$out" = "$expected" ]; then
-		echo "[ OK ]"
-		mptcp_lib_result_pass "${msg}"
+	# ${*} doesn't work here since there're spaces in some arguments.
+	mptcp_lib_check "${1}" "${2}" "${3}"
+	local rc=$?
+	if [ ${rc} -eq 0 ]; then
+		mptcp_lib_result_pass "${3}"
+	elif [ ${rc} -eq 1 ]; then
+		mptcp_lib_result_fail "${3} # different output"
 	else
-		echo -n "[FAIL] "
-		echo "expected '$expected' got '$out'"
-		mptcp_lib_result_fail "${msg} # different output"
-		ret=1
+		mptcp_lib_result_fail "${3} # error ${rc}"
 	fi
 }
 
-- 
2.35.3