OSU tests fail on IMPI due to warning msg

[sjpb]

All OSU test fails for alaska:ib-gcc9-impi-verbs and alaska:roce-gcc9-impi-verbs partitions.

The Intel MPI library emits the following to stdout, which is not handled by OMB output parser modules/omb.py:read_omb_out()

WARNING: release_mt library was used but no multi-ep feature was enabled. Please use release library instead.

[sjpb]

Hacky workaround by rewriting the output files to delete this warning added in 0fcbd4e