blktrace: Fix the blk_fill_rwbs() kernel-doc header

Reflect recent changes in the blk_fill_rwbs() kernel-doc header.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Chaitanya Kulkarni <kch@nvidia.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 919dbca8 ("blktrace: Use the new blk_opf_t type")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220715184735.2326034-3-bvanassche@acm.org


Signed-off-by: Jens Axboe <axboe@kernel.dk>