Fixed behavior if missing library cudnn.lib

AlexeyAB

2017-01-16 d7a30ada7e82daf7ce5ca91acac15c1723188fc5

 src/convolutional_kernels.cu

@@ -2,6 +2,10 @@
#include "curand.h"
#include "cublas_v2.h"

#ifdef CUDNN
#pragma comment(lib, "cudnn.lib")  
#endif

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