pgsql: Fix typo: < Currently indexes do not have enough tuple tuple

Log Message:
-----------
Fix typo:

<   Currently indexes do not have enough tuple tuple visibility
<   information to allow data to be pulled from the index without
<   also accessing the heap.  One way to allow this is to set a bit
<   to index tuples to indicate if a tuple is currently visible to
<   all transactions when the first valid heap lookup happens.  This
<   bit would have to be cleared when a heap tuple is expired.
>   Currently indexes do not have enough tuple visibility information
>   to allow data to be pulled from the index without also accessing
>   the heap.  One way to allow this is to set a bit to index tuples
>   to indicate if a tuple is currently visible to all transactions
>   when the first valid heap lookup happens.  This bit would have to
>   be cleared when a heap tuple is expired.

Modified Files:
--------------
    pgsql/doc:
        TODO (r1.1503 -> r1.1504)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1503&r2=1.1504)
    pgsql/doc/src/FAQ:
        TODO.html (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.10&r2=1.11)