Fix definition of MPI_BYTE

#define MPI_SEEK_SET SEEK_SET

#define MPI_SEEK_CUR SEEK_CUR

#define MPI_SEEK_END SEEK_END

#define MPI_BYTE 1 /* I need the size of the type here */

#define MPI_INFO_NULL 0

#define MPI_COMM_NULL 0

#define MPI_INT 1

#define MPI_CHAR 2

#define MPI_BYTE 2

#define MPI_DOUBLE 3

#define MPI_UNSIGNED 4

#define MPI_UNSIGNED_LONG 5