pgsql: Fix silly initializations (cosmetic only).

Fix silly initializations (cosmetic only).

Initializing a pointer to "false" isn't per project style,
and reportedly some compilers warn about it (though I've
not seen any such warnings in the buildfarm).

Seems to have come in with commit ff11e7f4b, so back-patch
to v12 where that was added.

Didier Gautheron

Discussion: https://postgr.es/m/CAJRYxu+XQuM0qnSqt1Ujztu6fBPzMMAT3VEn6W32rgKG6A2Fsw@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/0cafdd03a850265006c0ada1b0bf4f83e087a409

Modified Files
--------------
src/backend/commands/trigger.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)