generators: drop umask calls

systemd already sets the umask (see e3b8d0637d). When
running under systemd, we don't need to set it. And when *not* running under
systemd, for example during development, there is no reason to override the user
config. Let's just drop those calls.

$ git grep -e 'umask\(' -l 'src/*generator*' |xargs perl -i -0pe 's|^[^\n]*umask\([^\n]+\n\n||gms'

src/cryptsetup/cryptsetup-generator.c

@@ -585,8 +585,6 @@ int main(int argc, char *argv[]) {
 
         log_setup_generator();
 
-        umask(0022);
-
         arg_disks = hashmap_new(&string_hash_ops);
         if (!arg_disks) {
                 r = log_oom();