pgsql: Silence compiler warning - Mailing list pgsql-committers

Silence compiler warning

Introduced in de87a084c0a5.

Branch
------
REL_10_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/744639739c7c6a53bcbf4cd6fe765d7ebd89716a

Modified Files
--------------
src/backend/access/heap/heapam.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)