remove tensor moves

Author: Caroline Chen

torchaudio/prototype/rnnt_loss.py

@@ -105,16 +105,6 @@ def rnnt_loss(
             False  # softmax needs the original logits value
         )
 
-    # move everything to the same device.
-    targets = targets.to(device=logits.device)
-    logit_lengths = logit_lengths.to(device=logits.device)
-    target_lengths = target_lengths.to(device=logits.device)
-
-    # make sure all int tensors are of type int32.
-    targets = targets.int()
-    logit_lengths = logit_lengths.int()
-    target_lengths = target_lengths.int()
-
     if blank < 0:  # reinterpret blank index if blank < 0.
         blank = logits.shape[-1] + blank