Better check for whether or not to create the HDF5 groups for a given particle type

src/serial_io.c

@@ -702,7 +702,7 @@ void write_output_serial(struct engine* e, struct UnitSystem* us, int mpi_rank,
     for (int ptype = 0; ptype < NUM_PARTICLE_TYPES; ptype++) {
 
       /* Don't do anything if no particle of this kind */
-      if (numParticles[ptype] == 0) continue;
+      if (N_total[ptype] == 0) continue;
 
       /* Open the particle group in the file */
       char partTypeGroupName[PARTICLE_GROUP_BUFFER_SIZE];
@@ -736,7 +736,7 @@ void write_output_serial(struct engine* e, struct UnitSystem* us, int mpi_rank,
       for (int ptype = 0; ptype < NUM_PARTICLE_TYPES; ptype++) {
 
 	/* Don't do anything if no particle of this kind */
-	if (N[ptype] == 0) continue;
+	if (N_total[ptype] == 0) continue;
 
 	/* Open the particle group in the file */
 	char partTypeGroupName[PARTICLE_GROUP_BUFFER_SIZE];