Add "sss" to the automount database.  The sss service ordering is

based on passwd (and others; sss comes after files) and netgroup (sss

comes after nisplus).

Index: b/releng/nsswitch.conf

===================================================================

--- a/releng/nsswitch.conf

+++ b/releng/nsswitch.conf

@@ -59,6 +59,6 @@ netgroup:   nisplus sss

 publickey:  nisplus

-automount:  files nisplus

+automount:  files nisplus sss

 aliases:    files nisplus