Fixed behavior if missing library cudnn.lib

AlexeyAB

2017-01-15 3b9afd4cd2efcfeb9699f1d9658c8509e08e58fb

 src/avgpool_layer_kernels.cu

@@ -1,3 +1,7 @@
#include "cuda_runtime.h"
#include "curand.h"
#include "cublas_v2.h"

extern "C" {
#include "avgpool_layer.h"
#include "cuda.h"