BUG #18890: /src/timezone/localtime.c condition always false

The following bug has been logged on the website:

Bug reference:      18890
Logged by:          Daniel Elishakov
Email address:      dan-eli@mail.ru
PostgreSQL version: 17.4
Operating system:   Ubuntu 20.04
Description:        

On line 223 there is a check of string 'name' and in this case it is
initiallized and then is being checked for null once more with no reason.
The code becomes quite buggy.