vlc_GetCPUCount: use counting functions instead of loop

src/posix/thread.c

@@ -1038,10 +1038,7 @@ unsigned vlc_GetCPUCount(void)
     if (sched_getaffinity (getpid(), sizeof (cpu), &cpu) < 0)
         return 1;
 
-    unsigned count = 0;
-    for (unsigned i = 0; i < CPU_SETSIZE; i++)
-        count += CPU_ISSET(i, &cpu) != 0;
-    return count;
+    return CPU_COUNT (&cpu);
 
 #elif defined(__APPLE__)
     int count;

src/win32/thread.c

@@ -916,15 +916,7 @@ unsigned vlc_GetCPUCount (void)
     DWORD system;
 
     if (GetProcessAffinityMask (GetCurrentProcess(), &process, &system))
-    {
-        unsigned count = 0;
-        while (system)
-        {
-            count++;
-            system >>= 1;
-        }
-        return count;
-     }
+        return popcount (system);
 #endif
      return 1;
 }