block: fix virt_boundary handling in blk_validate_limits

Don't set the default max_segment_size value when a virt_boundary is
used.

Fixes: d690cb8a

 ("block: add an API to atomically update queue limits")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240221125010.3609444-1-hch@lst.de


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