Remove unnecessary function override in unpooling modules (#749)

Doing so breaks deserialization on systems with different
architectures. These operations are cheap, so it's not a
problem to perform them even when there's no unpooling
associated.

SpatialMaxPooling.lua

@@ -30,6 +30,11 @@ end
 
 function SpatialMaxPooling:updateOutput(input)
    self.indices = self.indices or input.new()
+
+   local dims = input:dim()
+   self.iheight = input:size(dims-1)
+   self.iwidth = input:size(dims)
+
    -- backward compatibility
    self.ceil_mode = self.ceil_mode or false
    self.padW = self.padW or 0

SpatialMaxUnpooling.lua

@@ -2,16 +2,9 @@ local SpatialMaxUnpooling, parent = torch.class('nn.SpatialMaxUnpooling', 'nn.Mo
 
 function SpatialMaxUnpooling:__init(poolingModule)
    parent.__init(self)
-   assert(torch.type(poolingModule)=='nn.SpatialMaxPooling', 'Argument must be a nn.SPatialMaxPooling module')
+   assert(torch.type(poolingModule)=='nn.SpatialMaxPooling', 'Argument must be a nn.SpatialMaxPooling module')
    assert(poolingModule.kH==poolingModule.dH and poolingModule.kW==poolingModule.dW, "The size of pooling module's kernel must be equal to its stride")
    self.pooling = poolingModule
-
-   poolingModule.updateOutput = function(pool, input)
-      local dims = input:dim()
-      pool.iheight = input:size(dims-1)
-      pool.iwidth = input:size(dims)
-      return nn.SpatialMaxPooling.updateOutput(pool, input)
-   end
 end
 
 function SpatialMaxUnpooling:setParams()

VolumetricMaxPooling.lua

@@ -36,6 +36,11 @@ function VolumetricMaxPooling:floor()
 end
 
 function VolumetricMaxPooling:updateOutput(input)
+   local dims = input:dim()
+   self.itime = input:size(dims-2)
+   self.iheight = input:size(dims-1)
+   self.iwidth = input:size(dims)
+
    self.indices = self.indices or input.new()
    input.THNN.VolumetricMaxPooling_updateOutput(
       input:cdata(),

VolumetricMaxUnpooling.lua

@@ -5,14 +5,6 @@ function VolumetricMaxUnpooling:__init(poolingModule)
   assert(torch.type(poolingModule)=='nn.VolumetricMaxPooling', 'Argument must be a nn.VolumetricMaxPooling module')
   assert(poolingModule.kT==poolingModule.dT and poolingModule.kH==poolingModule.dH and poolingModule.kW==poolingModule.dW, "The size of pooling module's kernel must be equal to its stride")
   self.pooling = poolingModule
-
-  poolingModule.updateOutput = function(pool, input)
-    local dims = input:dim()
-    pool.itime = input:size(dims-2)
-    pool.iheight = input:size(dims-1)
-    pool.iwidth = input:size(dims)
-    return nn.VolumetricMaxPooling.updateOutput(pool, input)
-  end
 end
 
 function VolumetricMaxUnpooling:setParams()