netlink-socket: Reorder elements in nl_dump structure.

netlink-socket: Reorder elements in nl_dump structure.

By reordering the elements in nl_dump structure, pad bytes can be
reduced there by saving a cache line.

Before: structure size:72, holes:1, sum padbytes:4, cachelines:2
After: structure size:64, holes:0, sum padbytes:0, cachelines:1

Signed-off-by: Bhanuprakash Bodireddy <bhanuprakash.bodireddy@intel.com>
Co-authored-by: Antonio Fischetti <antonio.fischetti@intel.com>
Signed-off-by: Antonio Fischetti <antonio.fischetti@intel.com>
Acked-by: Jarno Rajahalme <jarno@ovn.org>
Acked-by: Daniele Di Proietto <diproiettod@vmware.com>