revise error checking

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1932 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
silence compiler warnings

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1933 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
silence compiler warnings

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1934 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
older gcc complains warning: this decimal constant is unsigned only in ISO C90

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1935 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
this test program should run on 2 or more MPI processes

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1936 c368ceb8-fd28-0410-a457-e46ee1d7cd4a
add barrier because those processes with ranks > 4 may run too fast to read empty file

git-svn-id: https://svn.mcs.anl.gov/repos/parallel-netcdf/trunk@1937 c368ceb8-fd28-0410-a457-e46ee1d7cd4a