fix comment for Tensor.swish (#4604)

bad string replacement when we changed `function.` to `F.`

tinygrad/tensor.py

@@ -1160,7 +1160,7 @@ def reciprocal(self): return F.Reciprocal.apply(self.cast(least_upper_float(self
   def elu(self, alpha=1.0): return self.relu() - alpha*(1-self.exp()).relu()
   def celu(self, alpha=1.0): return self.maximum(0) + (alpha * ((self / alpha).exp() - 1)).minimum(0)
   def swish(self): return self * self.sigmoid()
-  def silu(self): return self.swish()   # The SiLU function is also known as the swish F.
+  def silu(self): return self.swish()   # The SiLU function is also known as the swish function.
   def relu6(self): return self.relu() - (self-6).relu()
   def hardswish(self): return self * (self+3).relu6() * (1/6)
   def tanh(self): return 2.0 * ((2.0 * self).sigmoid()) - 1.0