net: ena: cosmetic: code reorderings

1. Reorder sanity checks in get_comp_ctxt() to make more sense
2. Reorder variables in ena_com_fill_hash_function() and
   ena_calc_io_queue_size() in reverse christmas tree.
3. Move around member initializations.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>