pgsql: Fix misc typos.

Fix misc typos.

Oskari Saarenmaa. Backpatch to stable branches where applicable.

Branch
------
REL9_2_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/68f4b68e4e94d93941be54000c7f3dd8e11f9dee

Modified Files
--------------
contrib/btree_gist/btree_ts.c         |    2 +-
contrib/btree_gist/btree_utils_var.c  |    2 +-
src/backend/access/common/heaptuple.c |    2 +-
src/backend/access/gin/ginfast.c      |    4 ++--
src/backend/access/gist/gistproc.c    |    4 ++--
src/backend/optimizer/path/costsize.c |    2 +-
6 files changed, 8 insertions(+), 8 deletions(-)