perf record: Don't pass host machine to guest synthesizer

We were calling perf_session__process_machines(), that would first pass
the struct machine associated with the host to the provided callback,
perf_event__synthesize_guest_os() that would test if it was the host and
if so wouldn't do anything.

Ditch this contraption, just call directly machines__process with the
list of guests.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-x65vsxgzg4dvo3zqohtrrb9o@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-record.c

@@ -328,10 +328,6 @@ static void perf_event__synthesize_guest_os(struct machine *machine, void *data)
 {
 	int err;
 	struct perf_tool *tool = data;
-
-	if (machine__is_host(machine))
-		return;
-
 	/*
 	 *As for guest kernel when processing subcommand record&report,
 	 *we arrange module mmap prior to guest kernel mmap and trigger
@@ -574,9 +570,10 @@ static int __cmd_record(struct perf_record *rec, int argc, const char **argv)
 		       "Symbol resolution may be skewed if relocation was used (e.g. kexec).\n"
 		       "Check /proc/modules permission or run as root.\n");
 
-	if (perf_guest)
-		perf_session__process_machines(session, tool,
-					       perf_event__synthesize_guest_os);
+	if (perf_guest) {
+		machines__process(&session->machines,
+				  perf_event__synthesize_guest_os, tool);
+	}
 
 	if (!opts->target.system_wide)
 		err = perf_event__synthesize_thread_map(tool, evsel_list->threads,