[VPP-1578] VPP crashes when attempting to add 50k routes

[vvalderrv]

I'm not able to add more than approximately 38k routes into VPP before it crashes with the following traceback. I'm using VPP 19.01 with dpdk.

1. adding 50k routes
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: received signal SIGABRT, PC 0x7fa5ecb7253f
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: #0 0x00007fa5ed6d6ae8 0x7fa5ed6d6ae8
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Fixed: ip6_fib_dump #1 0x00007fa5ed41f030 0x7fa5ed41f030
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: add .gitlab-ci.yml in order to use ci/cd in gitlab #2 0x00007fa5ecb7253f gsignal + 0x10f
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: fix issue with missing sample_main in sample plugin #3 0x00007fa5ecb5c895 abort + 0x127
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: fix issue with missing sample_main in sample plugin #4 0x0000000000407223 0x407223
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: fix issue with missing sample_main in sample plugin #5 0x00007fa5ed1db775 vec_resize_allocate_memory + 0x395
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: fix packets redirect ineffective on af-packet interface #6 0x00007fa5ed692b65 vlib_validate_combined_counter + 0xc5
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Decrement n_retry in tx_burst_vector_internal #7 0x00007fa5edfb163f load_balance_create + 0x15f
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Stable/1810 #8 0x00007fa5edf8d5dd fib_entry_src_mk_lb + 0x10d
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Update stats.md #9 0x00007fa5edf8d956 fib_entry_src_action_install + 0x136
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Merge pull request #1 from FDio/master #10 0x00007fa5edf8ac21 fib_entry_create + 0x71
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: pci_dev in dpdk/device/cli.c for RTE_SCHED_COLLECT_STATS #11 0x00007fa5edf81965 fib_table_entry_path_add2 + 0x135
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: pci_dev in dpdk/device/cli.c for RTE_SCHED_COLLECT_STATS #12 0x00007fa5edc55ae0 0x7fa5edc55ae0
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: vpp crashes when attempting to run in kubernetes Pod  #13 0x00007fa5ed690d96 0x7fa5ed690d96
   Mar 04 17:26:30 nfvpe-02.oot.lab.eng.bos.redhat.com vnet[25931]: Merge pull request #1 from FDio/master #14 0x00007fa5ed6913d7 0x7fa5ed6913d7