securityselinuxhelper: Fix retval of setcon_raw() and security_disable()
securityselinuxhelper: Fix retval of setcon_raw() and security_disable()

The securityselinuxhelper is a mock that's replacing libselinux
APIs with our own implementation to achieve deterministic
results. Our implementation uses env vars (among other things) to
hold internal state. For instance, "FAKE_SELINUX_CONTEXT" and
"FAKE_SELINUX_DISABLED" variables are used. However, as we were
switching from setenv() to g_setenv() we also changed the set of
possible retvals from setcon_raw() and security_disable().
Previously, the retval of setenv() was used directly which
returns 0 on success and -1 on error. But g_setenv() has
different retval semantics: it returns 1 on success and 0 on
error.

This discrepancy can be observed by running viridentitytest where
case #2 reports an error ("!") - because setcon_raw() returns 1.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>

libvirt/libvirt,crobinso/libvirt,nertpinx/libvirt,libvirt/libvirt,jfehlig/libvirt,zippy2/libvirt,jfehlig/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,zippy2/libvirt,nertpinx/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt,crobinso/libvirt,libvirt/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,jfehlig/libvirt,jfehlig/libvirt,zippy2/libvirt