pgsql: fsync test files Prevent creation of 16GB files during fsync

Log Message:
-----------
fsync test files

Prevent creation of 16GB files during fsync testing; only create 16MB
files; backpatch to 8.4.X.

Modified Files:
--------------
pgsql/src/tools/fsync:
test_fsync.c (r1.24 -> r1.25)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/tools/fsync/test_fsync.c?r1=1.24&r2=1.25)