ksmbd: check protocol id in ksmbd_verify_smb_message()

When second smb2 pdu has invalid protocol id, ksmbd doesn't detect it
and allow to process smb2 request. This patch add the check it in
ksmbd_verify_smb_message() and don't use protocol id of smb2 request as
protocol id of response.

Reviewed-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: Ralph Böhme <slow@samba.org>
Reported-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>