fixed input for single thread symmetric matrix market files
Created by: rsln-s
The problem was as following:
If you use zdrive.exe to run phg hypergraph partitioning on a symmetric matrix market matrix (.mtx), it is not parsed correctly: "symmetric" keyword in the header is ignored, and instead of full matrix zoltan only sees it's upper triangle (e.g. 3elt matrix)
This pull requests fixes this input problem for single threaded, non-distributed case (and as far as my tests showed, doesn't break anything else).