Revert "Make scale in NonlinAttention have glu nonlinearity."

This reverts commit 048b6b6259a715c4b8225d493fdcd8df88e42b1f.

egs/librispeech/ASR/pruned_transducer_stateless7/zipformer.py

@@ -1602,7 +1602,7 @@ class NonlinAttention(nn.Module):
 
         self.hidden_channels = hidden_channels
 
-        self.in_proj = nn.Linear(channels, hidden_channels * 4, bias=True)
+        self.in_proj = nn.Linear(channels, hidden_channels * 3, bias=True)
 
         # balancer that goes before the sigmoid.  Have quite a large min_abs value, at 2.0,
         # because we noticed that well-trained instances of this module have abs-value before the sigmoid
@@ -1655,9 +1655,7 @@ attn_weights: a Tensor of shape (num_heads, batch_size, seq_len, seq_len)
         (seq_len, batch_size, _) = x.shape
         hidden_channels = self.hidden_channels
 
-        x, y = x.chunk(2, dim=-1)
-
-        s, x = x.chunk(2, dim=-1)
+        s, x, y = x.chunk(3, dim=-1)
 
         # s will go through tanh.
 
@@ -1679,7 +1677,7 @@ attn_weights: a Tensor of shape (num_heads, batch_size, seq_len, seq_len)
         # now x: (num_heads, batch_size, seq_len, head_dim)
         x = x.permute(2, 1, 0, 3).reshape(seq_len, batch_size, -1)
 
-        y = torch.nn.functional.glu(y, dim=-1)
+
         y = self.identity2(y)
         x = x * y
         x = self.identity3(x)