The previous patch did not provide protection for device lseek methods
(drivers/* stuff).  This patch pushes the BKL into each of the remaining
lseek methods -- without them we have a race.

I'd much prefer to have a a better lock to push down than the BKL, but
that will have to wait.

Before you balk at the size, remember patch #2 in this series which
removed much code ;-)

Thanks to Al for assistance, especially a listing of affected files.

	Robert Love