mailmap: map Stephen Smalley's old email addresses

Map old email addresses that are no longer in use to my current
email address.

Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

Author: stephensmalley

.mailmap

@@ -677,6 +677,8 @@ Stephen Hemminger <stephen@networkplumber.org> <shemminger@linux-foundation.org>
 Stephen Hemminger <stephen@networkplumber.org> <shemminger@osdl.org>
 Stephen Hemminger <stephen@networkplumber.org> <sthemmin@microsoft.com>
 Stephen Hemminger <stephen@networkplumber.org> <sthemmin@vyatta.com>
+Stephen Smalley <stephen.smalley.work@gmail.com> <sds@epoch.ncsc.mil>
+Stephen Smalley <stephen.smalley.work@gmail.com> <sds@tycho.nsa.gov>
 Steve Wise <larrystevenwise@gmail.com> <swise@chelsio.com>
 Steve Wise <larrystevenwise@gmail.com> <swise@opengridcomputing.com>
 Subash Abhinov Kasiviswanathan <quic_subashab@quicinc.com> <subashab@codeaurora.org>