pgsql: Fix typo in jsonfuncs.c.

Fix typo in jsonfuncs.c.

Author: Tatsuro Yamada
Discussion: https://postgr.es/m/7c166a60-2808-6b89-9524-feefc6233748@....jp_1

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/8ffb003591ff02f59d92c36a5791307881863146

Modified Files
--------------
src/backend/utils/adt/jsonfuncs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)