pgsql: Fix AcquireRewriteLocks to be sure that it acquires the right

Log Message:
-----------
Fix AcquireRewriteLocks to be sure that it acquires the right lock strength
when FOR UPDATE is propagated down into a sub-select expanded from a view.
Similar bug to parser's isLockedRel issue that I fixed yesterday; likewise
seems not quite worth the effort to back-patch.

Modified Files:
--------------
    pgsql/src/backend/rewrite:
        rewriteHandler.c (r1.190 -> r1.191)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/rewrite/rewriteHandler.c?r1=1.190&r2=1.191)
    pgsql/src/backend/utils/adt:
        ruleutils.c (r1.311 -> r1.312)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ruleutils.c?r1=1.311&r2=1.312)
    pgsql/src/include/rewrite:
        rewriteHandler.h (r1.31 -> r1.32)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/rewrite/rewriteHandler.h?r1=1.31&r2=1.32)