selftests/futex: Fix spelling mistake "Succeffuly" -> "Successfully"

There is a spelling mistake in a ksft_exit_fail_msg() message. Fix it.

Signed-off-by: Colin Ian King <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Link: https://lore.kernel.org/all/[e-mail]

tools/testing/selftests/futex/functional/futex_priv_hash.c

···
 	}
 	ret = pthread_mutex_timedlock(&lock, &timeout);
 	if (ret == 0)
-		ksft_exit_fail_msg("Succeffuly locked an already locked mutex.\n");
+		ksft_exit_fail_msg("Successfully locked an already locked mutex.\n");
 
 	if (ret != ETIMEDOUT)
 		ksft_exit_fail_msg("pthread_mutex_timedlock() did not timeout: %d.\n", ret);