gpu broadcast fix

src/layers/normalise.jl

@@ -116,7 +116,7 @@ BatchNorm(chs::Integer, λ = identity;
 function (BN::BatchNorm)(x)
   size(x, ndims(x)-1) == length(BN.β) ||
     error("BatchNorm expected $(length(BN.β)) channels, got $(size(x, ndims(x)-1))")
-  λ, γ, β = BN.λ, BN.γ, BN.β
+  γ, β = BN.γ, BN.β
   dims = length(size(x))
   channels = size(x, dims-1)
   affine_shape = ones(Int, dims)
@@ -140,7 +140,9 @@ function (BN::BatchNorm)(x)
     BN.σ = (1 - mtm) .* BN.σ .+ mtm .* squeeze(data(σ), (axes...)) .* m ./ (m - 1)
   end
 
-  λ.(reshape(γ, affine_shape...) .* ((x .- μ) ./ σ) .+ reshape(β, affine_shape...))
+  let λ = BN.λ
+    λ.(reshape(γ, affine_shape...) .* ((x .- μ) ./ σ) .+ reshape(β, affine_shape...))
+  end
 end
 
 children(BN::BatchNorm) =