Fix regression in 8bit parameter device movement (#1776)

Author: matthewdouglas

bitsandbytes/nn/modules.py

@@ -694,11 +694,10 @@ def to(self, *args, **kwargs):
         )
 
         # If we had already quantized, move the statistics appropriately.
-        if is_quantized and device is not None:
-            if self.CB is not None:
-                new_param.CB = new_param.data
+        if is_quantized:
+            new_param.CB = new_param.data
 
-            if self.SCB is not None:
+            if self.SCB is not None and device is not None:
                 new_param.SCB = self.SCB.to(device)
 
         return new_param