pgsql: Fix silly mistake in expand_indexqual_rowcompare --- in

Log Message:
-----------
Fix silly mistake in expand_indexqual_rowcompare --- in converting a forboth()
into an iteration over three parallel lists, I had accidentally put the lnext
steps outside the loop.  Sigh.  Per bug #3938.

Modified Files:
--------------
    pgsql/src/backend/optimizer/path:
        indxpath.c (r1.226 -> r1.227)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/indxpath.c?r1=1.226&r2=1.227)