[PATCH] selftests/ptp: Use kselftest skip code for skipped tests

[Po-Hsu Lin]

The phc.sh script in the ptp directory is still using exit 0 when
the test has been skipped due to some unmet requirements.
Use kselftest framework skip code instead so it can help us to
distinguish the return status.

Criterion to filter out what should be fixed in ptp directory:
  grep -r "exit 0" -B1 | grep -i skip

This change might cause some false-positives if people are running
these test scripts directly and only checking their return codes,
which will change from 0 to 4. However I think the impact should be
small as most of our scripts here are already using this skip code.
And there will be no such issue if running them with the kselftest
framework.

Note that there are some SKIP messages exit with 1, I leave those
unchanged.

Signed-off-by: Po-Hsu Lin <po-hsu.lin@xxxxxxxxxxxxx>
---
 tools/testing/selftests/ptp/phc.sh | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/ptp/phc.sh b/tools/testing/selftests/ptp/phc.sh
index ac6e5a6..0820544 100755
--- a/tools/testing/selftests/ptp/phc.sh
+++ b/tools/testing/selftests/ptp/phc.sh
@@ -1,6 +1,9 @@
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+# Kselftest framework requirement - SKIP code is 4.
+readonly KSFT_SKIP=4
+
 ALL_TESTS="
 	settime
 	adjtime
@@ -13,12 +16,12 @@ DEV=$1
 
 if [[ "$(id -u)" -ne 0 ]]; then
 	echo "SKIP: need root privileges"
-	exit 0
+	exit $KSFT_SKIP
 fi
 
 if [[ "$DEV" == "" ]]; then
 	echo "SKIP: PTP device not provided"
-	exit 0
+	exit $KSFT_SKIP
 fi
 
 require_command()
-- 
2.7.4