perf report: Fix warning assignment of 0/1 to bool variable

Fixes coccicheck warning:

  tools/perf/builtin-report.c:1403:2-34: WARNING: Assignment of 0/1 to bool variable
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1587904683-3510-1-git-send-email-zou_wei@huawei.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-report.c

@@ -1413,7 +1413,7 @@ int cmd_report(int argc, const char **argv)
 	}
 	if (branch_call_mode) {
 		callchain_param.key = CCKEY_ADDRESS;
-		callchain_param.branch_callstack = 1;
+		callchain_param.branch_callstack = true;
 		symbol_conf.use_callchain = true;
 		callchain_register_param(&callchain_param);
 		if (sort_order == NULL)