veriexec: Fix veriexec -i's confusion between loaded and locked states

Calling veriexec -i locked return the state of loaded and vice-versa.

Differential revision: https://reviews.freebsd.org/D30952
Reviewed by: sjg,imp
Obtained from: Stromshield

(cherry picked from commit 492bf4fdad4dbb96b82d88e12918e61042f71661)