bnxt_en: Fix ethtool selftest output in one of the failure cases

JIRA: https://issues.redhat.com/browse/RHEL-76568

commit 8e6cc90
Author: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Date:   Mon Apr 28 15:58:57 2025 -0700

    bnxt_en: Fix ethtool selftest output in one of the failure cases

    When RDMA driver is loaded, running offline self test is not
    supported and driver returns failure early. But it is not clearing
    the input buffer and hence the application prints some junk
    characters for individual test results.

    Fix it by clearing the buffer before returning.

    Fixes: 895621f ("bnxt_en: Don't support offline self test when RoCE driver is loaded")
    Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
    Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
    Signed-off-by: Michael Chan <michael.chan@broadcom.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Shruti Parab <shruti.parab@broadcom.com>

Author: Shruti Parab

drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -4999,14 +4999,14 @@ static void bnxt_self_test(struct net_device *dev, struct ethtool_test *etest,
 	if (!bp->num_tests || !BNXT_PF(bp))
 		return;
 
+	memset(buf, 0, sizeof(u64) * bp->num_tests);
 	if (etest->flags & ETH_TEST_FL_OFFLINE &&
 	    bnxt_ulp_registered(bp->edev)) {
 		etest->flags |= ETH_TEST_FL_FAILED;
 		netdev_warn(dev, "Offline tests cannot be run with RoCE driver loaded\n");
 		return;
 	}
 
-	memset(buf, 0, sizeof(u64) * bp->num_tests);
 	if (!netif_running(dev)) {
 		etest->flags |= ETH_TEST_FL_FAILED;
 		return;