cifs: Fix endian types in struct rfc1002_session_packet

All fields in struct rfc1002_session_packet are in big endian. This is
because all NetBIOS packet headers are in big endian as opposite of SMB
structures which are in little endian.

Therefore use __be16 and __be32 types instead of __u16 and __u32 in
struct rfc1002_session_packet.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>