Commit 95ffe19420 ("selinux: refactor mls_context_to_sid() and make
it stricter") inadvertently changed how we handle labels that did not
contain MLS information. This patch restores the proper behavior in
mls_context_to_sid() and adds a comment explaining the proper
behavior to help ensure this doesn't happen again.
Fixes: 95ffe19420 ("selinux: refactor mls_context_to_sid() and make it stricter")
Reported-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
877181a8d9