Fix BRIN minmax-multi distance for timetz type

The distance calculation ignored the time zone, so the result of (b-a)
might have ended negative even if (b > a). Fixed by considering the time
zone difference.

Reported-by: Jaime Casanova
Discussion: https://postgr.es/m/CAJKUy5jLZFLCxyxfT%3DMfK5mtPfSzHA1rVLowR-j4RRsFVvKm7A%40mail.gmail.com

src/backend/access/brin/brin_minmax_multi.c

@@ -2090,7 +2090,7 @@ brin_minmax_multi_distance_timetz(PG_FUNCTION_ARGS)
 	TimeTzADT  *ta = PG_GETARG_TIMETZADT_P(0);
 	TimeTzADT  *tb = PG_GETARG_TIMETZADT_P(1);
 
-	delta = tb->time - ta->time;
+	delta = (tb->time - ta->time) + (tb->zone - ta->zone) * USECS_PER_SEC;
 
 	Assert(delta >= 0);