toybox: Fix race condition during install

toybox: Fix race condition during install

 * It's possible that if we create a link which actually has a real
   package that the build system follows the link and ends up in place
   of the toybox binary. This is happening with blkid now, so remove
   it from the system image (and keep it for recovery)

Change-Id: I5efc471c5339a7718964698d23b955993a1f0563