hdf5_ep

Fixed a bug (HDFFV-10899) where the behavior of the deprecated
H5Gget_objinfo() call had changed and passing in a non-existing
soft link with a statbuf of NULL passed instead of failed (as
it should as per the RM). The HDF5 1.8 and 1.10 behavior was
restored and H5Gget_objinfo() will now fail and return -1 as
before.