fix: always pass bias arg in zero3_linear_wrap to avoid setup_context unpack error

Signed-off-by: Sung Hyun Cho <hope5487@gmail.com>

Author: roycho96

deepspeed/runtime/zero/linear.py

@@ -154,10 +154,7 @@ def backward(ctx, grad_output):
 
 
 def zero3_linear_wrap(input, weight, bias=None):
-    if bias is None:
-        return LinearFunctionForZeroStage3.apply(input, weight)
-    else:
-        return LinearFunctionForZeroStage3.apply(input, weight, bias)
+    return LinearFunctionForZeroStage3.apply(input, weight, bias)
 
 
 class LinearModuleForZeroStage3(Module):