bonding: fix a memory leak in bond_arp_send_all()

This test is reversed so the memory is always leaked.  It's better style
to remove the test anyway.

Fixes: 3e403a77 ('bonding: make it possible to have unlimited nested upper vlans')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Veaceslav Falico <vfalico@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>