vmxnet3: set carrier state properly on probe

vmxnet3 fails to set netif_carrier_off on probe, meaning that when an interface
is opened the __LINK_STATE_NOCARRIER bit is already cleared, and so
/sys/class/net/<ifname>/operstate remains in the unknown state.  Correct this by
setting netif_carrier_off on probe, like other drivers do.

Also, while we're at it, lets remove the netif_carrier_ok checks from the
link_state_update function, as that check is atomically contained within the
netif_carrier_[on|off] functions anyway

Tested successfully by myself

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: "VMware, Inc." <pv-drivers@vmware.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>