[CIFS] Fix minor endian error in durable handle patch series

Fix endian warning:

  CHECK   fs/cifs/smb2pdu.c
fs/cifs/smb2pdu.c:1068:40: warning: incorrect type in assignment (different base types)
fs/cifs/smb2pdu.c:1068:40:    expected restricted __le32 [usertype] Next
fs/cifs/smb2pdu.c:1068:40:    got unsigned long

Signed-off-by: Steve French <smfrench@gmail.com>