floppies must have been random in 2.x since we reintroduced sorting
on b_pblkno on 1995/03/18. Drivers still initialize b_cylin/b_resid
although this is no longer used.
Removed unused, wrong function fdsize(). (Returning 0 means that the
device exists and has size 0, not that the device doesn't exist.
swaponvp() allows for size 0 by stupidly calling the d_psize function
twice if the size isn't 0. setdumpdev() doesn't allow for it.)
Continued removing /* ARGSUSED */ from drivers.
27513ca73b