I think the declaration is more
static void THNN_Floatim2col(const float* data_im, const int channels,
      const int height, const int width, const int kernel_h, const int kernel_w,
      const int pad_h, const int pad_w,
      const int stride_h, const int stride_w,
      const int dilation_h, const int dilation_w,
      float* data_col);

or so (by literally copying the declaration in the file and substituting).
From the message, you seem to have an extra underscore somewhere.
Best regards
Thomas