dev_set_promiscuity/allmulti might overflow.
Commit: "netdevice: Fix promiscuity and allmulti overflow" in net-next makes
dev_set_promiscuity/allmulti return error number if overflow happened.

In bond_alb and bond_main, we check all positive increment for promiscuity
and allmulti to get error return.
But there are still two problems left.
1. Some code path has no mechanism to signal errors upstream.
2. If there are multi slaves, it's hard to tell which slaves increment
   promisc/allmulti successfully and which failed.
So I left these problems to be FIXME.
Fortunately, the overflow is very rare case.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>