Enabling/disabling of allmulticast mode is not always successful and
it should be taken into account to be able to handle it properly.
When correct return status is unclear from driver code, -EAGAIN is used.
Signed-off-by: Ivan Ilchenko <ivan.ilchenko@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Acked-by: Hyong Youb Kim <hyonkim@cisco.com>