If rte_stats_bitrate_reg() or rte_stats_bitrate_calc() are
passed NULL as the parameter for the stats structure, the
result is a crash. Fixed by adding a sanity check that makes
sure the passed-in pointer is not NULL.
Fixes: 2ad7ba9a6567 ("bitrate: add bitrate statistics library")
Cc: stable@dpdk.org
Signed-off-by: Remy Horton <remy.horton@intel.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>