pgsql: Cast to (void *) rather than (int *) when passing int64's to PQf

Cast to (void *) rather than (int *) when passing int64's to PQfn().

This is a possibly-vain effort to silence a Coverity warning about
bogus endianness dependency.  The code's fine, because it takes care
of endianness issues for itself, but Coverity sees an int64 being
passed to an int* argument and not unreasonably suspects something's
wrong.  I'm not sure if putting the void* cast in the way will shut it
up; but it can't hurt and seems better from a documentation standpoint
anyway, since the pointer is not used as an int* in this code path.

Just for a bit of additional safety, verify that the result length
is 8 bytes as expected.

Back-patch to 9.3 where the code in question was added.

Branch
------
REL9_3_STABLE

Details
-------
http://git.postgresql.org/pg/commitdiff/d16d821faa5a2c97e2fb532daa9a032b48129c91

Modified Files
--------------
src/interfaces/libpq/fe-lobj.c |   10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)