net: ena: fix retrieval of nonadaptive interrupt moderation intervals

BugLink: https://bugs.launchpad.net/bugs/1853180

Nonadaptive interrupt moderation intervals are assigned the value set
by the user in ethtool -C divided by ena_dev->intr_delay_resolution.

Therefore when the user tries to get the nonadaptive interrupt moderation
intervals with ethtool -c the code needs to multiply the saved value
by ena_dev->intr_delay_resolution.

The current code erroneously divides instead of multiplying in ethtool -c.
This patch fixes this.
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 0eda8479)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Acked-by: Khaled Elmously <khalid.elmously@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/net/ethernet/amazon/ena/ena_ethtool.c

@@ -310,14 +310,15 @@ static int ena_get_coalesce(struct net_device *net_dev,
 		/* the devie doesn't support interrupt moderation */
 		return -EOPNOTSUPP;
 	}
+
 	coalesce->tx_coalesce_usecs =
-		ena_com_get_nonadaptive_moderation_interval_tx(ena_dev) /
+		ena_com_get_nonadaptive_moderation_interval_tx(ena_dev) *
 			ena_dev->intr_delay_resolution;
 
 	if (!ena_com_get_adaptive_moderation_enabled(ena_dev))
 		coalesce->rx_coalesce_usecs =
 			ena_com_get_nonadaptive_moderation_interval_rx(ena_dev)
-			/ ena_dev->intr_delay_resolution;
+			* ena_dev->intr_delay_resolution;
 
 	coalesce->use_adaptive_rx_coalesce =
 		ena_com_get_adaptive_moderation_enabled(ena_dev);