Fix tools/cudnn2cunn.lua no effect

tools/cudnn2cunn.lua

@@ -9,8 +9,8 @@ require 'cudnn'
 require 'w2nn'
 local srcnn = require 'srcnn'
 
-local function cudnn2cunn(cunn_model)
-   local cudnn_model = srcnn.waifu2x_cunn(srcnn.channels(cunn_model))
+local function cudnn2cunn(cudnn_model)
+   local cunn_model = srcnn.waifu2x_cunn(srcnn.channels(cudnn_model))
    local weight_from = cudnn_model:findModules("cudnn.SpatialConvolution")
    local weight_to = cunn_model:findModules("nn.SpatialConvolutionMM")