match with ncdump that allows one input file only

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1588 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
match with ncdump that allows one input file only

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1589 c368ceb8-fd28-0410-a457-e46ee1d7cd4a