Some comment problem in nodeAgg.c

Hi

When looking into the code about hash disk,
I found some comment in nodeAgg.c may have not been updated.

1. Since function lookup_hash_entry() has been deleted,
there are still some comment talk about lookup_hash_entry().

 * and is packed/unpacked in lookup_hash_entry() / agg_retrieve_hash_table()
 ...
 * GROUP BY columns.  The per-group data is allocated in lookup_hash_entry(),
 ...
 * Be aware that lookup_hash_entry can reset the tmpcontext.


2. Now we can use hash_mem_multiplier to set hashagg's mem limit,
   The comment in hash_agg_set_limits() still use "work mem" like the following.

    /*
     * Don't set the limit below 3/4 of hash_mem. In that case, we are at the
     * minimum number of partitions, so we aren't going to dramatically exceed
     * ## work mem ## anyway.

Does it mean hash_mem here?

Best regards,
houzj