perf test: Use machine__new_host in mmap thread lookup test

This is more straightforward than what we have now.

It also fixes a segfault within machine__exit, that's caused by not
creating kernel maps for machine.. We're calling
machine__destroy_kernel_maps in machine__exit since commit:

ebe9729c8c31 perf machine: Fix to destroy kernel maps when machine exits

Signed-off-by: Jiri Olsa <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Tested-by: Arnaldo Carvalho de Melo <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Masami Hiramatsu <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/tests/mmap-thread-lookup.c

···
 
 static int mmap_events(synth_cb synth)
 {
-	struct machines machines;
 	struct machine *machine;
 	int err, i;
 
···
 	 */
 	TEST_ASSERT_VAL("failed to create threads", !threads_create());
 
-	machines__init(&machines);
-	machine = &machines.host;
+	machine = machine__new_host();
 
 	dump_trace = verbose > 1 ? 1 : 0;
 
···
 	}
 
 	machine__delete_threads(machine);
-	machines__exit(&machines);
+	machine__delete(machine);
 	return err;
 }