Fix functionality of RBSTATS when using ROS3

[srosanka]

Contact:
Simon Rosanka, University of California, Irvine (UCI)

Type of code change:
bug fix

Description of changes:
Compiling CMAQ crashes when using the conditional rbstats option due to incorrectly referencing XMSG as error message. This was fixed by referencing MSG, which is used for error messages within rbdriver.F. In addition, the Intel compiler complained about the incorrect declaration of STATOUT, which was fixed as well.

Issue:
Does not resolve any known issue. The frozen main branch is also affected by this issue.

Summary of Impact:
No impact on model predictions.

Tests conducted:
These code changes were tested by compiling CMAQ using the Intel compiler with OpenMPI, followed by a standard run test. Following these changes, the rbstats output is created as intended.

[kmfoley]

@srosanka Thank you for alerting us to this bug in rbdriver.F. The developer that maintains this part of the code, @bhutzell, agrees with the changes that you have proposed. He warns that changes will also be needed to your include file and run script to successfully use the CPP flag. Without changing the FILES_CTM.EXT file and run-script, the model creates an output file with the same name, CTM_RBSTATS_1, while the run-script does not allow removal of the output so the model can crash. Let us know if you need additional information.

We will merge this PR into the 5.4+ branch and it will be included in the next CMAQ release. Thank you for your contribution!

[srosanka]

@kmfoley Thank you very much for merging these changes so quickly and providing additional information. I am always happy to help!