s3:smbd: disconnect the socket if we got an unexpected request

s3:smbd: disconnect the socket if we got an unexpected request

If we got a SMB2_OP_NEGPROT after the protocol is already negotiated
or if we got a non SMB2_OP_NEGPROT before the protocol was negotiated
we should close the connection (as windows does).

metze

Autobuild-User: Stefan Metzmacher <metze@samba.org>
Autobuild-Date: Fri Sep 23 12:30:50 CEST 2011 on sn-devel-104
(cherry picked from commit 5494856294384df4360d85e68abc03c43dc16e06)
(cherry picked from commit 8d54841f640212a5c3d026df3fbfd1f7c99ac7f7)