smb/server: remove unused nterr.h

KSMBD does not use these NT error code definitions. Instead, it uses the
SMB2 status code definitions defined in common/smb2status.h.

By the way, server/nterr.h contains the following additional definitions
compared to client/nterr.h:

  - NT_STATUS_PENDING
  - NT_STATUS_INVALID_LOCK_RANGE
  - NT_STATUS_NETWORK_SESSION_EXPIRED
  - NT_STATUS_NO_PREAUTH_INTEGRITY_HASH_OVERLAP

We can add them to client/nterr.h in the next patch.

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: ChenXiaoSong