machinectl: remove dead code

'r' is not touched after the previous error-checking 100 lines above. Drop
that code.

src/machine/machinectl.c

@@ -250,9 +250,6 @@ static int list_images(int argc, char *argv[], void *userdata) {
                        (int) max_mtime, strna(format_timestamp(mtime_buf, sizeof(mtime_buf), images[j].mtime)));
         }
 
-        if (r < 0)
-                return bus_log_parse_error(r);
-
 
         if (arg_legend)
                 printf("\n%zu images listed.\n", n_images);