Merge branch 'fix_gcc7' into 'master'

Fix int-in-bool-context with gcc-7.2

With GCC-7.2.0, I am getting the following error:
<code>
scheduler.c:1606:14: error: ‘<<’ in boolean context, did you mean ‘<’ ? [-Werror=int-in-bool-context]
     if (!((1 << t->type)) || t->skip) continue;
          ~~~~^~~~~~~~~~~~
</code>

See merge request !444

src/parallel_io.c

@@ -347,7 +347,7 @@ void writeArray(struct engine* e, hid_t grp, char* fileName, FILE* xmfFile,
   }
 
   /* Make sure the chunks are not larger than the dataset */
-  if (chunk_shape[0] > (hsize_t) N_total) chunk_shape[0] = N_total;
+  if (chunk_shape[0] > (hsize_t)N_total) chunk_shape[0] = N_total;
 
   /* Create the space in the file */
   hid_t h_filespace = H5Screate(H5S_SIMPLE);

src/scheduler.c

@@ -1603,7 +1603,7 @@ void scheduler_print_tasks(const struct scheduler *s, const char *fileName) {
 
   for (int k = nr_tasks - 1; k >= 0; k--) {
     t = &tasks[tid[k]];
-    if (!((1 << t->type)) || t->skip) continue;
+    if (t->skip) continue;
     fprintf(file, "%d %s %s %d %d\n", k, taskID_names[t->type],
             subtaskID_names[t->subtype], t->nr_unlock_tasks, t->wait);
   }