Fixed behavior if missing library cudnn.lib

AlexeyAB

2017-01-15 3b9afd4cd2efcfeb9699f1d9658c8509e08e58fb

 src/convolutional_kernels.cu

@@ -2,6 +2,8 @@
#include "curand.h"
#include "cublas_v2.h"

#pragma comment(lib, "cudnn.lib")  

extern "C" {
#include "convolutional_layer.h"
#include "batchnorm_layer.h"