timer_create01: accept ENOTSUP

CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM require an RTC with alarm
support, which may not be present on a system. In that case, the kernel
will return EOPNOTSUPP, which is defined as ENOTSUP in userspace.

As these clocks are already possibly unsupported, accept that as an error
code besides the EINVAL code.

Note that previously the kernel would incorrectly return the ENOTSUPP code,
which is undefined in userspace. With these unfixed kernels, the test will
fail when those RTCs are not present.

Kernel was fixed to return correct errno in:
f18ddc13af98 ("alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP").

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Reviewed-by: Cyril Hrubis <chrubis@suse.cz>

Author: Thadeu Lima de Souza Cascardo

testcases/kernel/syscalls/timer_create/timer_create01.c

@@ -18,6 +18,9 @@
  *	3) SIGEV_THREAD
  *	4) SIGEV_THREAD_ID
  *	5) NULL
+ *
+ * This is also regression test for commit:
+ * f18ddc13af98 ("alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP")
  */
 
 #include <signal.h>
@@ -77,7 +80,8 @@ static void run(unsigned int n)
 				&created_timer_id));
 
 		if (TST_RET != 0) {
-			if (possibly_unsupported(clock) && TST_ERR == EINVAL) {
+			if (possibly_unsupported(clock) &&
+			    (TST_ERR == EINVAL || TST_ERR == ENOTSUP)) {
 				tst_res(TPASS | TTERRNO,
 					"%s unsupported, failed as expected",
 					get_clock_str(clock));