pgsql: Avoid need for E'' construct by using regexp instead of LIKE.

Log Message:
-----------
Avoid need for E'' construct by using regexp instead of LIKE. More
readable, and more like the other places in this file.

Modified Files:
--------------
pgsql/src/bin/psql:
describe.c (r1.121 -> r1.122)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/describe.c.diff?r1=1.121&r2=1.122)