netxen: reversed condition in netxen_nic_set_link_parameters()

My static checker complains that we are using "autoneg" without
initializing it.  The problem is the ->phy_read() condition is reversed
so we only set this on error instead of success.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>