selftests: timers: Fix run_destructive_tests target to handle skipped tests

When a test exits with skip exit code of 4, "make run_destructive_tests"
halts testing. Fix run_destructive_tests target to handle error exit codes.

Cc: stable <stable@vger.kernel.org> [4.13+]
Reported-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/timers/Makefile

@@ -13,20 +13,20 @@ TEST_GEN_PROGS_EXTENDED = alarmtimer-suspend valid-adjtimex adjtick change_skew
 
 include ../lib.mk
 
+define RUN_DESTRUCTIVE_TESTS
+	@for TEST in $(TEST_GEN_PROGS_EXTENDED); do \
+		BASENAME_TEST=`basename $$TEST`;	\
+		if [ ! -x $$BASENAME_TEST ]; then	\
+			echo "selftests: Warning: file $$BASENAME_TEST is not executable, correct this.";\
+			echo "selftests: $$BASENAME_TEST [FAIL]"; \
+		else					\
+			cd `dirname $$TEST`; (./$$BASENAME_TEST && echo "selftests: $$BASENAME_TEST [PASS]") || echo "selftests:  $$BASENAME_TEST [FAIL]"; cd -;\
+		fi;					\
+	done;
+endef
+
 # these tests require escalated privileges
 # and may modify the system time or trigger
 # other behavior like suspend
 run_destructive_tests: run_tests
-	./alarmtimer-suspend
-	./valid-adjtimex
-	./adjtick
-	./change_skew
-	./skew_consistency
-	./clocksource-switch
-	./freq-step
-	./leap-a-day -s -i 10
-	./leapcrash
-	./set-tz
-	./set-tai
-	./set-2038
-
+	$(RUN_DESTRUCTIVE_TESTS)