fix MPI tags where greater than MPI_TAG_UB

While writing data as pvtp on NERSC's Cray XC30, in some case
ParaView crashed with the error:

  MPI_Recv(113): Invalid tag, value is 3389002

This patch reduces tag values used in MPI send/recv calls
below reported value of MPI_TAG_UB.

  MPI VERSION = CRAY MPICH version 7.0.0 (ANL base 3.1)
  MPI_TAG_UB = 2097151

Change-Id: I1a867a1e2f61f425fbf59dc19283106e7693226a
Merge topic 'fix-mpi-tag-ub' into next

f91b31b6 fix MPI tags where greater than MPI_TAG_UB