develop: Fix hang bug by updating MPI bcast to be from 0 not IAPROC-1

[JessicaMeixner-NOAA]

Pull Request Summary

This PR fixes the bcast call.

Description

When saving point for the unstructured grid, the bcast root was incorrectly IAPROC-1 instead of 0 as intended. This PR is a bug fix and the same bug fix for the dev/ufs-weather-model branch has corresponding PR #1426

Issue(s) addressed

Refs #1350

Commit Message

Fix hang bug by updating MPI bcast to be from 0 not IAPROC-1

Check list

• Branch is up to date with the authoritative repository (NOAA-EMC) develop branch.
• Checked the checklist for a developer submitting to develop.
• If a version number update is required, checked the updating version number checklist.
• If a new feature was added, a regression test for testing the new feature is added.

Testing

• How were these changes tested? matrix regtests
• Are the changes covered by regression tests? (If not, why? Do new tests need to be added?) yes, although you usually saw the hang on higher processor counts.
• Have the matrix regression tests been run (if yes, please note HPC and compiler)? hera intel
• Please indicate the expected changes in the regression test output, (Note the list of known non-identical tests.)
  only the expected non b4b
• Please provide the summary output of matrix.comp (matrix.Diff.txt, matrixCompFull.txt and matrixCompSummary.txt):

**********************************************************************
********************* non-identical cases ****************************
**********************************************************************
mww3_test_03/./work_PR1_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_e_c                     (1 files differ)
mww3_test_03/./work_PR2_UQ_MPI_e                     (1 files differ)
mww3_test_03/./work_PR2_UNO_MPI_e                     (1 files differ)
mww3_test_03/./work_PR2_UNO_MPI_d2                     (9 files differ)
mww3_test_03/./work_PR1_MPI_d2                     (14 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2_c                     (10 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2_c                     (16 files differ)
mww3_test_03/./work_PR3_UNO_MPI_d2                     (16 files differ)
mww3_test_03/./work_PR2_UQ_MPI_d2                     (15 files differ)
mww3_test_03/./work_PR3_UQ_MPI_e                     (1 files differ)
mww3_test_03/./work_PR3_UQ_MPI_d2                     (16 files differ)
mww3_test_09/./work_MPI_ASCII                     (0 files differ)
ww3_tp2.10/./work_MPI_OMPH                     (6 files differ)
ww3_tp2.16/./work_MPI_OMPH                     (4 files differ)
ww3_tp2.6/./work_ST4_ASCII                     (0 files differ)
ww3_ufs1.3/./work_a                     (3 files differ)

matrixCompFull.txt
matrixCompSummary.txt
matrixDiff.txt

[sbanihash]

I have reviewed and tested this PR and approve the changes.

matrixCompSummary.txt
matrixCompFull.txt
matrixDiff.txt

*will not merge since Ming is also testing this PR.

[mingchen-NOAA]

I have reviewed and tested this PR.

matrixCompFull.txt
matrixCompSummary.txt
matrixDiff.txt