scripts: fix file writing in convert-variable-renames
In my test environments (Fedora 35 and Debian 10.10 on AMD 2970WX),
running the convert-variable-renames.py rename script was resulting
in empty files instead of updated ones. From inspection, the new
files are never flushed/closed before moving them into place, which
seems inherently racy. Adding an explicit close to flush the modified
contents out before moving into place fixes the issue for me.
Signed-off-by: Scott Murray <scott.murray@konsulko.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
