[PATCH] USB ATM: fix line resync logic

We map states 0x00 and 0x10 to the ATM_PHY_SIG_LOST flag.  The current logic fails to
resync the line if we get state 0x10 followed by 0x00, since we only resync the line
when the state is 0x00 and the flag changed.  Doubly fixed by (1) always resyncing the
line when the state is 0x00 even if the state didn't change, and (2) keeping track of
the last state, not just the flag.  We do (2) as well as (1) in order to get better log
messages.

This is a tweaked version of the original patch by Aurelio Arroyo.

Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>