Do not use altroot while creating the pool

altroot is not a persistent option and since its a new pool we can trust
the directories will not interfere with the system.

Ticket:	#6994
Revert "Better error message."

This reverts commit 8624e94e97a1646256d14ab59e5fd3434b272d24.

Ticket: #6994
Revert "Workaround a bug by not allowing volume names that would trip the bug."

This reverts commit bf061ac3282ca765dc7253916062aebfee2ea84a.

Ticket: #6994