net/mlx5e: Fix ETHTOOL_GRXCLSRLALL handling

Handler for ETHTOOL_GRXCLSRLALL must set info->data to the size
of the table, regardless of the amount of entries in it.
Existing code does not do that, and this breaks all usage of ethtool -N
or -n without explicit location, with this error:
rmgr: Invalid RX class rules table size: Success

Set info->data to the table size.

Tested:
ethtool -n ens8
ethtool -N ens8 flow-type ip4 src-ip 1.1.1.1 dst-ip 2.2.2.2 action 1
ethtool -N ens8 flow-type ip4 src-ip 1.1.1.1 dst-ip 2.2.2.2 action 1 loc 55
ethtool -n ens8
ethtool -N ens8 delete 1023
ethtool -N ens8 delete 55

Fixes: f913a72a

 ("net/mlx5e: Add support to get ethtool flow rules")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>