bonding: remove the return value for bond_3ad_bind_slave()

I'm sure the operand slave and bond for the function will not
be NULL, so the check for the bond will not make any sense, so
remove the judgement, and the return value was useless here,
remove the unwanted return value.

The comments for the bond 3ad is too old, cleanup some errors
and warming.

Signed-off-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_3ad.h b/drivers/net/bonding/bond_3ad.h
index 5d91ad0..13dc9d3 100644
--- a/drivers/net/bonding/bond_3ad.h
+++ b/drivers/net/bonding/bond_3ad.h
@@ -265,7 +265,7 @@
 
 // ================= AD Exported functions to the main bonding code ==================
 void bond_3ad_initialize(struct bonding *bond, u16 tick_resolution);
-int  bond_3ad_bind_slave(struct slave *slave);
+void  bond_3ad_bind_slave(struct slave *slave);
 void bond_3ad_unbind_slave(struct slave *slave);
 void bond_3ad_state_machine_handler(struct work_struct *);
 void bond_3ad_initiate_agg_selection(struct bonding *bond, int timeout);