Fix some compiler warnings

Fix some compiler warnings

Some of the buildfarm members with some old gcc versions have been
complaining about an always-true test for a NULL pointer caused by a
combination of SOFT_ERROR_OCCURRED() and a local ErrorSaveContext
variable.

These warnings are taken care of by removing SOFT_ERROR_OCCURRED(),
switching to a direct variable check, like 56b1e88c804b.

Oversights in e1405aa5e3ac and 44eba8f06e55.

Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/1341064.1764895052@sss.pgh.pa.us