ice: remove unnecessary check for old MAC == new MAC

The check has been moved to core. The ndo_set_mac_address callback
is not being called with new MAC address equal to the old one anymore.

Signed-off-by: Piotr Gardocki <piotrx.gardocki@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>