[Fix]: Fix logging of validation loss (#9663)

Author: eantono

mmdet/models/detectors/base.py

@@ -263,8 +263,13 @@ def val_step(self, data, optimizer=None):
         losses = self(**data)
         loss, log_vars = self._parse_losses(losses)
 
+        log_vars_ = dict()
+        for loss_name, loss_value in log_vars.items():
+            k = loss_name + '_val'
+            log_vars_[k] = loss_value
+
         outputs = dict(
-            loss=loss, log_vars=log_vars, num_samples=len(data['img_metas']))
+            loss=loss, log_vars=log_vars_, num_samples=len(data['img_metas']))
 
         return outputs