perf report: Fix segmentation fault when running with '-g none'

Segmentation fault occurs when running perf report with '-g
none'.
Reported-by: NAustin Zhang <austin.zhang@intel.com>
Signed-off-by: NYong Wang <yong.y.wang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100122014750.GA4111@ywang-moblin2.bj.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

tools/perf/builtin-report.c

@@ -269,7 +269,7 @@ parse_callchain_opt(const struct option *opt __used, const char *arg,
 
 	else if (!strncmp(tok, "none", strlen(arg))) {
 		callchain_param.mode = CHAIN_NONE;
-		symbol_conf.use_callchain = true;
+		symbol_conf.use_callchain = false;
 
 		return 0;
 	}