chore(image): reduce warning level for src being NULL (#8394)

Signed-off-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

src/widgets/image/lv_image.c

@@ -820,6 +820,11 @@ static void draw_image(lv_event_t * e)
 
         if(img->h == 0 || img->w == 0) return;
         if(img->scale_x == 0 || img->scale_y == 0) return;
+        if(img->src == NULL) {
+            /*Do not need to draw image when src is NULL*/
+            LV_LOG_TRACE("image source is NULL");
+            return;
+        }
 
         lv_layer_t * layer = lv_event_get_layer(e);
 
@@ -905,10 +910,6 @@ static void draw_image(lv_event_t * e)
             }
             lv_draw_label(layer, &label_dsc, coords);
         }
-        else if(img->src == NULL) {
-            /*Do not need to draw image when src is NULL*/
-            LV_LOG_WARN("image source is NULL");
-        }
         else {
             /*Trigger the error handler of image draw*/
             LV_LOG_WARN("image source type is unknown");