pgsql: Silence compiler warning in assertion-enabled builds.

Silence compiler warning in assertion-enabled builds.

With -Wtype-limits, gcc correctly points out that size_t can never be < 0.
Backpatch to 9.3 and 9.2. It's been like this forever, but in <= 9.1 you got
a lot other warnings with -Wtype-limits anyway (at least with my version of
gcc).

Andres Freund

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/d2e71ff7573e67fc0a263d0ba6fe2ffbc175d1ad

Modified Files
--------------
src/pl/plpython/plpy_procedure.c |    4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)