net/mlx5e: Set local Xoff after FW update

The local Xoff value is being set before the firmware (FW) update.
In case of a failure where the FW is not updated with the new value,
there is no fallback to the previous value.
Update the local Xoff value after the FW has been successfully set.

Fixes: 0696d608 ("net/mlx5e: Receive buffer configuration")
Signed-off-by: Alexei Lazar <alazar@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250825143435.598584-12-mbloch@nvidia.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>