pgsql: Fix breakage introduced in plpgsql CONTINUE patch.

Log Message:
-----------
Fix breakage introduced in plpgsql CONTINUE patch.
Per Kevin McArthur.

Modified Files:
--------------
pgsql/src/pl/plpgsql/src:
pl_exec.c (r1.149 -> r1.150)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c.diff?r1=1.149&r2=1.150)