Correctly name the thread-plot output files taking into account thread 0

examples/main.c

@@ -530,7 +530,7 @@ int main(int argc, char *argv[]) {
 
       /* Make sure output file is empty, only on one rank. */
       char dumpfile[30];
-      snprintf(dumpfile, 30, "thread_info_MPI-step%d.dat", j);
+      snprintf(dumpfile, 30, "thread_info_MPI-step%d.dat", j + 1);
       FILE *file_thread;
       if (myrank == 0) {
         file_thread = fopen(dumpfile, "w");
@@ -582,7 +582,7 @@ int main(int argc, char *argv[]) {
 
 #else
       char dumpfile[30];
-      snprintf(dumpfile, 30, "thread_info-step%d.dat", j);
+      snprintf(dumpfile, 30, "thread_info-step%d.dat", j + 1);
       FILE *file_thread;
       file_thread = fopen(dumpfile, "w");
       /* Add some information to help with the plots */