selftests: futex: convert test to use ksft TAP13 framework

Convert test to use ksft TAP13 framework to print user friendly
test output which is consistent across kselftest suite.

Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

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

@@ -68,9 +68,10 @@ int main(int argc, char *argv[])
 		}
 	}
 
-	printf("%s: Block on a futex and wait for timeout\n",
+	ksft_print_header();
+	ksft_print_msg("%s: Block on a futex and wait for timeout\n",
 	       basename(argv[0]));
-	printf("\tArguments: timeout=%ldns\n", timeout_ns);
+	ksft_print_msg("\tArguments: timeout=%ldns\n", timeout_ns);
 
 	/* initialize timeout */
 	to.tv_sec = 0;