As tx mbuf is not set for some advanced descriptors, if there is no
mbuf checking before rte_pktmbuf_free_seg() function be called on
the process of tx done clean up, that will cause a segfault. So add
a NULL pointer check to fix it.
Bugzilla ID: 501
Fixes: 8d907d2b79f7 ("net/igb: free consumed Tx buffers on demand")
Cc: stable@dpdk.org
Signed-off-by: Jeff Guo <jia.guo@intel.com>
Reviewed-by: Wei Zhao <wei.zhao1@intel.com>
4237be2b9e