net: ena: make ethtool show correct current and max queue sizes

Currently ethtool -g shows the same size for current and max queue
sizes.

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