actually fixing the bug on the time kernel counter

Author: dkazanc

httomo/method_wrappers/generic.py

@@ -334,7 +334,7 @@ def execute(self, block: T) -> T:
             block = self._run_method(block, args)
             block = self._postprocess_data(block)
 
-        if self.is_cpu:
+        if self.is_gpu:
             self._gpu_time_info.kernel = t.elapsed
         else:
             self._gpu_time_info.kernel = 0