xfs: simplify xfs_buf_submit_bio

Convert the __bio_add_page(..., virt_to_page(), ...) pattern to the
bio_add_virt_nofail helper implementing it and use bio_add_vmalloc
to insulate xfs from the details of adding vmalloc memory to a bio.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250507120451.4000627-16-hch@lst.de


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