tileset_read_toplevel() leaks spec_filenames on error
Noticed when working on #46411, but the bug exist both before and after that patch: tileset_read_toplevel() scanning of spec file list uses goto on error, and thus skips "free(spec_filenames);" on the list it was processing.
Noticed when working on #46411, but the bug exist both before and after that patch: tileset_read_toplevel() scanning of spec file list uses goto on error, and thus skips "free(spec_filenames);" on the list it was processing.