Avoid reading process IO info multiple times on multithreaded processes.

Bugfix from Gerhard Heift.

ProcessList.c

@@ -565,10 +565,6 @@ static bool ProcessList_processEntries(ProcessList* this, char* dirname, Process
             process->tgid = parent->pid;
          }
 
-         #ifdef HAVE_TASKSTATS        
-         ProcessList_readIoFile(this, process, dirname, name);
-         #endif
-
          if (showUserlandThreads && (!parent || pid != parent->pid)) {
             char subdirname[MAX_NAME+1];
             snprintf(subdirname, MAX_NAME, "%s/%s/task", dirname, name);
@@ -577,6 +573,10 @@ static bool ProcessList_processEntries(ProcessList* this, char* dirname, Process
                continue;
          }
 
+         #ifdef HAVE_TASKSTATS        
+         ProcessList_readIoFile(this, process, dirname, name);
+         #endif
+
          process->updated = true;
 
          if (!existingProcess)