Revision 330524

MFC r324940:

Fix the error message when creating a zpool on a too-small device

Don't check for SPA_MINDEVSIZE in vdev_geom_attach when opening by path.
It's redundant with the check in vdev_open, and failing to attach here
results in the wrong error message being printed.  However, still check for
it in some other situations:

* When opening by guids, so we don't get bogged down reading from slow
  devices like floppy drives.
* In vdev_geom_read_pool_label for the same reason, because we iterate over
  all providers.
* If the caller requests that we verify the guid, because then we'll have to
  read from the device before vdev_open verifies the size.

PR:		222227
Reported by:	Marie Helene Kvello-Aune <marieheleneka@gmail.com>
Reviewed by:	avg, mav
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D12531