Make mokutil use libefivar.

There's really no need to have a second (old) variable library embedded here.

Note that this requires efivar-0.12 .

Signed-off-by: Peter Jones <pjones@redhat.com>
strlen() is unsigned, so most things we compare loop indices to are.

So use unsigned types for those things.

Signed-off-by: Peter Jones <pjones@redhat.com>
Actually limit our text conversion to pw_len (implicitly +1 for L'\0')

Signed-off-by: Peter Jones <pjones@redhat.com>