md: Fix logical_block_size configuration being overwritten

md: Fix logical_block_size configuration being overwritten

In super_1_validate(), mddev->logical_block_size is directly overwritten
with the value from metadata. This causes the previously configured lbs
to be lost, making the configuration ineffective. Fix it.

Fixes: 62ed1b582246 ("md: allow configuring logical block size")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Link: https://lore.kernel.org/linux-raid/20251226024221.724201-1-linan666@huaweicloud.com
Signed-off-by: Yu Kuai <yukuai@fnnas.com>