s3: smbd: Codenomicon crash in do_smb_load_module().

s3: smbd: Codenomicon crash in do_smb_load_module().

Inside api_pipe_bind_req() we look for a pipe module name using

dcerpc_default_transport_endpoint(pkt,
                                NCACN_NP, table)

which returns NULL when given invalid pkt data from the Codenomicon fuzzer.

This gets passed directly to smb_probe_module(), which then calls
do_smb_load_module() which tries to deref the (NULL) module name.

https://bugzilla.samba.org/show_bug.cgi?id=11342

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ira Cooper <ira@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Thu Jun 18 22:14:01 CEST 2015 on sn-devel-104