md/raid5-ppl: Fix argument order in bio_alloc_bioset()

bio_alloc_bioset() takes a block device, number of vectors, the
OP flags, the GFP mask and the bio set. However when the prototype
was changed, the callisite in ppl_do_flush() had the OP flags and
the GFP flags reversed. This introduced some sparse error:

  drivers/md/raid5-ppl.c:632:57: warning: incorrect type in argument 3
				    (different base types)
  drivers/md/raid5-ppl.c:632:57:    expected unsigned int opf
  drivers/md/raid5-ppl.c:632:57:    got restricted gfp_t [usertype]
  drivers/md/raid5-ppl.c:633:61: warning: incorrect type in argument 4
  				    (different base types)
  drivers/md/raid5-ppl.c:633:61:    expected restricted gfp_t [usertype]
				    gfp_mask
  drivers/md/raid5-ppl.c:633:61:    got unsigned long long

The sparse error introduction may not have been reported correctly by
0day due to other work that was cleaning up other sparse errors in this
area.

Fixes: 609be106

 ("block: pass a block_device and opf to bio_alloc_bioset")
Cc: stable@vger.kernel.org # 5.18+
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>