pgsql: Revert based on Tom's recommendation: > Allow VACUUM to complete

Log Message:
-----------
Revert based on Tom's recommendation:

> Allow VACUUM to complete faster by avoiding scanning the indexes when no
> rows were removed from the heap by the VACUUM.

Modified Files:
--------------
pgsql/src/backend/access/gist:
gistvacuum.c (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gist/gistvacuum.c.diff?r1=1.12&r2=1.13)
pgsql/src/backend/access/hash:
hash.c (r1.84 -> r1.85)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/hash/hash.c.diff?r1=1.84&r2=1.85)
pgsql/src/backend/access/index:
indexam.c (r1.88 -> r1.89)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/index/indexam.c.diff?r1=1.88&r2=1.89)
pgsql/src/backend/access/nbtree:
nbtree.c (r1.137 -> r1.138)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/nbtree/nbtree.c.diff?r1=1.137&r2=1.138)
pgsql/src/backend/commands:
vacuum.c (r1.322 -> r1.323)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuum.c.diff?r1=1.322&r2=1.323)
vacuumlazy.c (r1.64 -> r1.65)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/vacuumlazy.c.diff?r1=1.64&r2=1.65)
pgsql/src/include/access:
genam.h (r1.55 -> r1.56)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/access/genam.h.diff?r1=1.55&r2=1.56)