Move the declaration of freerq() to request.h.
logrq: add support for lock events.
vinumstart: solve a problem where removing a plex from an active
volume could cause attempts to access non-existent plexes.
launch_requests: don't set a request group active until we're sure we
can launch it. This caused some hangs under unusual
circumstances.
bre: don't set XFR_BAD_SUBDISK if we're not going to use it.
build_read_request: correct recovery, which caused some hangs under
(other) unusual circumstances.
build_rq_buffer: don't set bp->b_dev if we don't have a dev.
sdio: clean up, remove obsolete code.
deallocrqg: unlock any locks the rqg may have.