dup_sec_desc does not duplicate SE_DESC_DACL_AUTO_INHERITED

[Matt Seitz]

The dup_sec_desc function (rpc_parse/parse_sec.c) does not duplicate the 
SE_DESC_DACL_AUTO_INHERITED flag.  However, sec_desc_equal does check 
this flag.  This means that

      assert(sec_desc_equal(sd, dup_sec_desc(ctx, sd));

will fail if "(sd->type & SE_DESC_DACL_AUTO_INHERITED) != 0" is true.

Is this a bug or is there a reason for this behavior?