restore a few more mixin aliases for now

lib/msf/core/exploit/smb/client.rb

@@ -16,6 +16,10 @@ module Msf
       include Msf::Exploit::Remote::Tcp
       include Msf::Exploit::Remote::NTLM::Client
 
+      # These constants are unused here, but may be used in some code that
+      # includes this. Local definitions should be preferred.
+      SIMPLE = Rex::Proto::SMB::SimpleClient
+      XCEPT  = Rex::Proto::SMB::Exceptions
       CONST  = Rex::Proto::SMB::Constants
 
       # Alias over the Rex DCERPC protocol modules