set the correct defines for the thread-safe HDF5 functions.

Former-commit-id: 451931f9664da5a0930ce0f48585ec9885e1e97c

src/common_io.c

@@ -31,6 +31,9 @@
 #include <stddef.h>
 #include <hdf5.h>
 #include <math.h>
+#ifdef WITH_MPI
+#include <mpi.h>
+#endif
 
 #include "const.h"
 #include "cycle.h"

src/parallel_io.c

@@ -23,6 +23,8 @@
 
 #if defined(HAVE_HDF5) && defined(WITH_MPI)
 
+/* Tell HDF5 that we're interested in using shared-memory parallel stuff. */
+#define H5_HAVE_PARALLEL
 
 /* Some standard headers. */
 #include <stdio.h>