[TextGeneration][Bug] Fix timer (#1294)

* create new timer if none

* move timer check/creation to timer.py

Author: dsikka

src/deepsparse/transformers/engines/nl_decoder_engine.py

@@ -185,7 +185,7 @@ def __call__(
 
         :return: The generated token and corresponding logits
         """
-        timer = self.timer_manager.current
+        timer = self.timer_manager.current_or_new()
         if kv_cache:
             # if model has kv cache enabled, we need
             # to add the kv cache state to the input

src/deepsparse/utils/timer.py

@@ -338,6 +338,16 @@ def all_times(self) -> Dict[str, List[float]]:
 
         return all_times
 
+    def current_or_new(self) -> StagedTimer:
+        """
+        Return the current timer if there is one, otherwise return a new one.
+        """
+        if self.current:
+            return self.current
+        else:
+            with self.new_timer_context(total_inference=False) as timer:
+                return timer
+
     def clear(self):
         for t in self._timers:
             t.clear()