net-bonding: Fix minor sparse complaints

This gets rid of minor sparse complaints:
drivers/net/bonding/bond_main.c:4361:4: warning: do-while statement is not a compound statement
drivers/net/bonding/bond_main.c:243:12: warning: symbol 'bond_mode_name' was not declared. Should it be static?

Signed-off-by: David Decotigny <decot@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>