perf session: Use sample->machine_pid to find guest machine

If machine_pid is set, use it to find the guest machine.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: kvm@vger.kernel.org
Link: https://lore.kernel.org/r/20220711093218.10967-15-adrian.hunter@intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1418,7 +1418,9 @@ static struct machine *machines__find_for_cpumode(struct machines *machines,
 	     (sample->cpumode == PERF_RECORD_MISC_GUEST_USER))) {
 		u32 pid;
 
-		if (event->header.type == PERF_RECORD_MMAP
+		if (sample->machine_pid)
+			pid = sample->machine_pid;
+		else if (event->header.type == PERF_RECORD_MMAP
 		    || event->header.type == PERF_RECORD_MMAP2)
 			pid = event->mmap.pid;
 		else