vchoi_fork

[svn-r24612] fix bugs in parallel tests exposed in corner cases when running with 1
or 2 processes.

First bug is in testpar/t_mdset.c, where the test reports an error in
addition to skipping the test if there are less than three procs. Fix
to just skip the test.

Second bug is in testpar/t_dset.c in actual_io_mode tests, where
incorrect expected value for IO mode was set if the number of procs
running the test is 1.

tested with h5committest.