ZTS: Enable zpool_create_008_pos.ksh

Remove the blkid version check from zpool_create_008_pos.ksh
so the test case will not be skipped.

All versions of blkid tested by the CI are either new enough
to not suffer from this issue, or have been patched as is
the case with CentOS 7 (libblkid-2.23.2-61).

Additionally, add a block_device_wait after device partitioning
to ensure the expected partitions will exist.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #9853