UPstream.C uses wrong getenv

[spikebike]

I was having persistent errors with running OpenFoam-6 (just downloaded) and having MPI_BUFFER_SIZE undefined. This is on an openmpi-4.0.1 + ubuntu 18.04 system and I'm 100% sure that the same OpenMPI was used to compile and run.

This happened when launched with mpirun or srun.

This did not help:
export MPI_BUFFER_SIZE=2000000

Nor did telling mpirun to pass in the variable with -x.

I recommend on line 123 of UPstream.c you call getenv, not getEnv.

Also if it's undefined I'd either set a default, or just skip the call to MPI_Buffer_attach.

With the above mentioned change it seems to work well.