kni: fix kernel crash with multi-segments

kni: fix kernel crash with multi-segments

va2pa depends on the physical address and virtual address offset of
current mbuf. It may get the wrong physical address of next mbuf which
allocated in another hugepage segment.

In rte_mempool_populate_default(), trying to allocate whole block of
contiguous memory could be failed. Then, it would reserve memory in
several memzones that have different physical address and virtual address
offsets. The rte_mempool_populate_default() is used by
rte_pktmbuf_pool_create().

Fixes: 8451269e6d7b ("kni: remove continuous memory restriction")
Cc: stable@dpdk.org
Signed-off-by: Yangchao Zhou <zhouyates@gmail.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>