messaging: fix net command failure due to unhandled return code

messaging: fix net command failure due to unhandled return code

messaging_init_internal() blanket returned NT_STATUS_INTERNAL_ERROR
instead of correctly changing the return code to an NTSTATUS code. Also
return more appropriate mem error.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=12828

Signed-off-by: David Mulder <dmulder@suse.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>
Autobuild-User(master): David Disseldorp <ddiss@samba.org>
Autobuild-Date(master): Thu Jun  8 08:04:05 CEST 2017 on sn-devel-144