net/mlx5: fix Verbs memory allocation callback

net/mlx5: fix Verbs memory allocation callback

The rdma-core library uses callbacks to allocate and free memory
from DPDK. The memory allocation callback used the complicated
and incorrect way to get the NUMA socket ID from the context.
The context was wrong that might result in wrong socket ID
and allocating memory from wrong node.

The callbacks are assigned once as Infinibande device context
is created allowing early access to shared DPDK memory for all
Verbs internal objects need that.

Fixes: 36dabcea78f0 ("net/mlx5: use anonymous Direct Verbs allocator argument")
Fixes: 2eb4d0107acc ("net/mlx5: refactor PCI probing on Linux")
Fixes: 17e19bc4dde7 ("net/mlx5: add IB shared context alloc/free functions")
Cc: stable@dpdk.org
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>