securityselinuxtest: Don't leak @mgr
securityselinuxtest: Don't leak @mgr

The security manager is created so that test cases can use it.
However, it is never released.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

jfehlig/libvirt,zippy2/libvirt,zippy2/libvirt,crobinso/libvirt,libvirt/libvirt,jardasgit/libvirt,olafhering/libvirt,andreabolognani/libvirt,libvirt/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,nertpinx/libvirt,zippy2/libvirt,eskultety/libvirt,olafhering/libvirt,jfehlig/libvirt,nertpinx/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,eskultety/libvirt,crobinso/libvirt,eskultety/libvirt,jardasgit/libvirt,andreabolognani/libvirt,andreabolognani/libvirt,eskultety/libvirt,andreabolognani/libvirt,jardasgit/libvirt,andreabolognani/libvirt,nertpinx/libvirt,olafhering/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,crobinso/libvirt,crobinso/libvirt,zippy2/libvirt,jardasgit/libvirt,libvirt/libvirt,libvirt/libvirt,jfehlig/libvirt,eskultety/libvirt