[MASSMAIL]pgsql: Suppress "variable may be used uninitialized" warning.

Suppress "variable may be used uninitialized" warning.

Buildfarm member caiman is showing this, which surprises me because
it's very late-model gcc (14.0.1) and ought to be smart enough to
know that elog(ERROR) doesn't return.  But we're likely to see the
same from stupider compilers too, so add a dummy initialization in
our usual style.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/3c5ff36aba8a3df19967d0ddc1249c63417bb9b0

Modified Files
--------------
src/backend/parser/parse_expr.c | 1 +
1 file changed, 1 insertion(+)