wrong comments in rewriteTargetListIU

[jian he]

hi.

in function, rewriteTargetListIU
we have:

for (attrno = 1; attrno <= numattrs; attrno++)
{
            /*
             * Can only insert DEFAULT into generated columns, regardless of
             * any OVERRIDING clauses.
             */
            if (att_tup->attgenerated && !apply_default)
}

I think the above comments are wrong, since there are no
OVERRIDING clauses for the generated column.