fuzzing: Fix test failure with G_DISABLE_ASSERT
https://gitlab.gnome.org/GNOME/glib/-/jobs/1875915
../fuzzing/fuzz_paths.c: In function ‘LLVMFuzzerTestOneInput’:
../fuzzing/fuzz_paths.c:7:16: error: variable ‘skipped_root’ set but not used [-Werror=unused-but-set-variable]
7 | const gchar *skipped_root;
| ^~~~~~~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Philip Withnall pwithnall@endlessos.org