resubmit bridge: fix message_age_timer calculation
This changes the message_age_timer calculation to use the BPDU's max age as
opposed to the local bridge's max age. This is in accordance with section
8.6.2.3.2 Step 2 of the 802.1D-1998 sprecification.
With the current implementation, when running with very large bridge
diameters, convergance will not always occur even if a root bridge is
configured to have a longer max age.
Tested successfully on bridge diameters of ~200.
Signed-off-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>