Don't set NUM_GLOBAL_PARTS for Zoltan

[benfulton]

In Zoltan, you can set either NUM_LOCAL_PARTS or NUM_GLOBAL_PARTS but you should not set both. Setting both NUM_GLOBAL_PARTS and NUM_LOCAL_PARTS together has issues.

[Patol75]

Just for context, I found the following in the Zoltan source code. It does not seem to me that setting both NUM_GLOBAL_PARTS and NUM_LOCAL_PARTS is prohibited, but there appears to be a compatibility pattern to respect between the two. Are we actually breaking it?

[benfulton]

I discussed this with Stephan but could have written it up better here. We attempted to run flredecomp on 4 nodes, 64 cores per node and thus passed -o 256 as a parameter. The result was the error

Sum of NUM_LOCAL_PARTS 256 < NUM_GLOBAL_PARTS 512

and a failure in Zoltan_LB_Partition (which I discovered after I replaced the assert(ierr) with an FLAbort). I assume the 512 is due to flredcomp setting 256 global parts and also one local part per rank, although I couldn't verify that in the Zoltan code. I opened a Trilinos discussion and was told that it is not recommended to set both. This PR appears to fix the issue although we are still trying to get Fluidity running.