When a context is pulled in from disk we don't know that it is null
terminated.  This patch forecebly null terminates contexts when we pull
them from disk.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>