selftests: ublk: mark each test start and end time in dmesg

Log test start and end time in dmesg, so generated log messages
during the test run can be linked to specific test from the test
suite.

Signed-off-by: Alexander Atanasov <alex@zazolabs.com>

Author: zazolabs

tools/testing/selftests/ublk/test_common.sh

@@ -121,6 +121,7 @@ _prep_test() {
 	modprobe ublk_drv > /dev/null 2>&1
 	UBLK_TMP=$(mktemp ublk_test_XXXXX)
 	[ "$UBLK_TEST_QUIET" -eq 0 ] && echo "ublk $type: $*"
+	echo "ublk selftest: $TID starting at $(date --iso-8601=sec)" | tee /dev/kmsg
 }
 
 _remove_test_files()
@@ -165,6 +166,7 @@ _cleanup_test() {
 	"${UBLK_PROG}" del -a
 
 	_remove_files
+	echo "ublk selftest: $TID done at $(date --iso-8601=sec)" | tee /dev/kmsg
 }
 
 _have_feature()