perf tools: Check libaudit availability for perf-trace builtin

The newly added trace command requires an external audit library.

However it can cause a build error because it's not checked whether the
libaudit is installed on system:

    CC builtin-trace.o
  builtin-trace.c:7:22: fatal error: libaudit.h: No such file or directory
  compilation terminated.
  make: *** [builtin-trace.o] Error 1

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1348745018-21744-1-git-send-email-namhyung@kernel.org
[ committer note: Added ", disables 'trace tool' to the feature warning msg ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 3fb052c..fc2f770 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -55,7 +55,9 @@
 	{ "lock",	cmd_lock,	0 },
 	{ "kvm",	cmd_kvm,	0 },
 	{ "test",	cmd_test,	0 },
+#ifndef NO_LIBAUDIT_SUPPORT
 	{ "trace",	cmd_trace,	0 },
+#endif
 	{ "inject",	cmd_inject,	0 },
 };