perf kvm stat report: Enable the target.system_wide flag

The 'perf kvm stat report' command can be used to analyze events either
for system wide or for specific pids.

Let's enable kvm->opts.target.system_wide flag when 'report' command is
running for system-wide analyzing. This helps to sync kvm->opts.target
values in 'report' and 'live' commands.

Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1409579095-12963-3-git-send-email-yarygin@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-kvm.c

@@ -1207,6 +1207,9 @@ kvm_events_report(struct perf_kvm_stat *kvm, int argc, const char **argv)
 					   kvm_events_report_options);
 	}
 
+	if (!kvm->opts.target.pid)
+		kvm->opts.target.system_wide = true;
+
 	return kvm_events_report_vcpu(kvm);
 }