This patch changes when we decide what the device's MAC address
is from per ifconfig up to once when the device is connected.

Without this patch, a manually forced device MAC is overwritten
on ifconfig down/up.  Also devices that have no EEPROM are
assigned a new random address on ifconfig down/up instead of
persisting the same one.
Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Reported-by: Robert Cunningham <rcunningham@nsmsurveillance.com>
Cc: Bjorn Mork <bjorn@mork.no>
Cc: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>