jumbo+iavf buffer alloc error: loadbalancer

[vrpolakatcisco]

Previously reported as one of symptoms of generic jumbo+avf ticket [0]. Still present [0] in rls2506. Tracking as a separate bug, because similar issues ([2] for vhost and [3] for memif) while have similar symptoms, might need fixes specific processing code, not in common device code. This is because most other jumbo tests are passing.

[0] https://github.com/FDio/vpp/issues/3548 [1] https://logs.fd.io/vex-yul-rot-jenkins-1/csit-vpp-perf-report-coverage-2506-2n-emr/8/log.html.gz#s1-s1-s1-s1-s1-t6-k3-k7-k1-k1-k1-k8-k14-k1-k1-k1-k1 [2] https://github.com/FDio/csit/issues/4033 [3] https://github.com/FDio/vpp/issues/3552