Revert "Workaround issue of Linux vdev_disk.c, (#16678)"

Now that we can handle these different alignments, we don't this
workaround.

This reverts commit aefc2da8a594d7a8059c862eab464d5f798393b3.

Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Closes #16687