For trace file which is generated by spdk trace_record,
if one lcore recorded no entries, there is no space for
it to have idle entries to referring.
Change-Id: I1cd89ec934407fc805bda66c8c87f76cb181679e
Signed-off-by: Xiaodong Liu <xiaodong.liu@intel.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/449840
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
1468f8dd3b