Linux: zero CPU data after allocation

Zero all the CPU data, like totalPeriod, after its memory allocation via
realloc(3).

    Conditional jump or move depends on uninitialised value(s)
       at 0x132A9B: LinuxProcessList_scanCPUTime (LinuxProcessList.c:1928)
       by 0x1358C3: ProcessList_goThroughEntries (LinuxProcessList.c:2079)
        by 0x12A79A: ProcessList_scan (ProcessList.c:627)
        by 0x11CA67: CommandLine_run (CommandLine.c:357)
        by 0x4A81E49: (below main) (libc-start.c:314)
      Uninitialised value was created by a heap allocation
        at 0x48396C5: malloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
        by 0x12F633: xRealloc (XUtils.c:64)
        by 0x12F633: xReallocArray (XUtils.c:78)
        by 0x1325A8: LinuxProcessList_updateCPUcount (LinuxProcessList.c:207)
        by 0x134E0A: ProcessList_new (LinuxProcessList.c:284)
        by 0x11C8D0: CommandLine_run (CommandLine.c:301)
        by 0x4A81E49: (below main) (libc-start.c:314)

linux/LinuxProcessList.c

@@ -167,11 +167,11 @@ static void LinuxProcessList_updateCPUcount(ProcessList* super) {
 
    DIR* dir = opendir("/sys/devices/system/cpu");
    if (!dir) {
-      super->activeCPUs = 1;
-      super->existingCPUs = 1;
-      this->cpuData = xReallocArray(this->cpuData, 2, sizeof(CPUData));
+      this->cpuData = xReallocArrayZero(this->cpuData, super->existingCPUs ? (super->existingCPUs + 1) : 0, 2, sizeof(CPUData));
       this->cpuData[0].online = true; /* average is always "online" */
       this->cpuData[1].online = true;
+      super->activeCPUs = 1;
+      super->existingCPUs = 1;
       return;
    }
 
@@ -204,10 +204,7 @@ static void LinuxProcessList_updateCPUcount(ProcessList* super) {
       /* readdir() iterates with no specific order */
       unsigned int max = MAXIMUM(existing, id + 1);
       if (max > currExisting) {
-         this->cpuData = xReallocArray(this->cpuData, max + /* aggregate */ 1, sizeof(CPUData));
-         for (unsigned int j = currExisting; j < max; j++) {
-            this->cpuData[j].online = false;
-         }
+         this->cpuData = xReallocArrayZero(this->cpuData, currExisting ? (currExisting + 1) : 0, max + /* aggregate */ 1, sizeof(CPUData));
          this->cpuData[0].online = true; /* average is always "online" */
          currExisting = max;
       }