Fix for pg_upgrade tablespace function usage

I have applied the attached patch to git head to fix the new SQL tablespace
location function usage in pg_upgrade to properly check cluster version
numbers, and a fix missing table alias.

I found this problem during testing.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +