Stop smb2 from calling into smb1 blocking lock request code.

Stop smb2 from calling into smb1 blocking lock request code.

Allocate a uint16_t internal SMB1 mid for an SMB2 request.
Add a back pointer from the faked up smb_request struct
to the smb2 request.

Getting ready to add restart code for blocking locks,
share mode violations and oplocks in SMB2.

Jeremy.