[smatch] re: bonding:delete lacp_fast from ad_bond_info

[Dan Carpenter <error27@gmail.com>]

There was a dereference before a check added in 56d00c677de0a
"bonding:delete lacp_fast from ad_bond_info"

drivers/net/bonding/bond_3ad.c +1907 bond_3ad_bind_slave(7)
	warn: variable dereferenced before check 'bond'

  1900  int bond_3ad_bind_slave(struct slave *slave)
  1901  {
  1902          struct bonding *bond = bond_get_bond_by_slave(slave);
  1903          int lacp_fast = bond->params.lacp_fast;
                                ^^^^^^^^^^^^
	dereference.

  1904          struct port *port;
  1905          struct aggregator *aggregator;
  1906  
  1907          if (bond == NULL) {
                    ^^^^^^^^^^^^
	check.

  1908                  pr_err("%s: The slave %s is not attached to its bond\n",
  1909                         slave->dev->master->name, slave->dev->name);
  1910                  return -1;
  1911          }

regards,
dan carpenter