pgsql: Use OIDCHARS: Use OIDCHARS for oid character length, rather than

Log Message:
-----------
Use OIDCHARS:

Use OIDCHARS for oid character length, rather than '10', in tablespace
code.

Modified Files:
--------------
pgsql/src/backend/commands:
tablespace.c (r1.66 -> r1.67)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/tablespace.c?r1=1.66&r2=1.67)