utils: apply access rules to load/load2 in one shot

Open load/load2 only once. Inside the callback only collect rules
using smack_accessed_add_from_file(). Finally, apply access rules
in a single slot.

This was inspired by feedback from Rafal Krypa <r.krypa@samsung.com>.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>