udev: firmware - disable firmware loading when firmware file is 0 byte

If firmware file is not found in the file system, udev
terminates firmware loading. This is not the case if
firmware file exists in the file system but doesn't have
any data in it.

src/udev/udev-builtin-firmware.c

@@ -140,9 +140,12 @@ static int builtin_firmware(struct udev_device *dev, int argc, char *argv[], boo
         }
 
         if (stat(fwpath, &statbuf) < 0 || statbuf.st_size == 0) {
+                if (!in_initrd())
+                        set_loading(udev, loadpath, "-1");
                 rc = EXIT_FAILURE;
                 goto exit;
         }
+
         if (unlink(misspath) == 0)
                 util_delete_path(udev, misspath);