Change g_displayLevel to int and fix DISPLAYUPDATE flush

lib/dictBuilder/cover.c

@@ -59,8 +59,6 @@ static int g_displayLevel = 2;
     if ((clock() - g_time > refreshRate) || (displayLevel >= 4)) {             \
       g_time = clock();                                                        \
       DISPLAY(__VA_ARGS__);                                                    \
-      if (displayLevel >= 4)                                                   \
-        fflush(stdout);                                                        \
     }                                                                          \
   }
 #define DISPLAYUPDATE(l, ...) LOCALDISPLAYUPDATE(g_displayLevel, l, __VA_ARGS__)

lib/dictBuilder/zdict.c

@@ -480,7 +480,7 @@ static size_t ZDICT_trainBuffer(dictItem* dictList, U32 dictListSize,
 #   define DISPLAYUPDATE(l, ...) if (notificationLevel>=l) { \
             if (ZDICT_clockSpan(displayClock) > refreshRate)  \
             { displayClock = clock(); DISPLAY(__VA_ARGS__); \
-            if (notificationLevel>=4) fflush(stdout); } }
+            if (notificationLevel>=4) fflush(stderr); } }
 
     /* init */
     DISPLAYLEVEL(2, "\r%70s\r", "");   /* clean display line */