pgsql: Use macro atooid() for conversion of strings to oids, per sugges

Use macro atooid() for conversion of strings to oids, per suggestion
from Tom.

Branch
------
master

Details
-------
http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=807005c024aa57b5af729d021263cbf179fd5121

Modified Files
--------------
contrib/pg_upgrade/info.c | 8 ++++----
contrib/pg_upgrade/pg_upgrade.h | 2 ++
contrib/pg_upgrade/relfilenode.c | 4 ++--
3 files changed, 8 insertions(+), 6 deletions(-)