handle case when running more than 4 processes

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1862 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
handle case when running more than 4 processes

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1863 c368ceb8-fd28-0410-a457-e46ee1d7cd4a