semctl09: Fix EPERM warning in cleanup()

If semctl09 failed in one of the SAFE_*() functions during unprivileged user
test case, SAFE_SEMCTL() in cleanup() would fail with EPERM because the sem_id
is owned by root. Make sure that cleanup() always runs with root EUID.

Fixes: 2a3e43a ("syscalls/ipc: semctl09: add a test for SEM_STAT_ANY")

Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Martin Doucha <mdoucha@suse.cz>

testcases/kernel/syscalls/ipc/semctl/semctl09.c

@@ -187,6 +187,8 @@ static void setup(void)
 
 static void cleanup(void)
 {
+	SAFE_SETEUID(root_uid);
+
 	if (sem_id >= 0)
 		SAFE_SEMCTL(sem_id, 0, IPC_RMID);
 }