!4471 fix caffe prelu

Merge pull request !4471 from zhaodezan/master

mindspore/lite/src/runtime/kernel/arm/fp32/caffeprelu.cc

@@ -59,7 +59,7 @@ int CaffePReluCPUKernel::Run() {
   output_data = reinterpret_cast<float *>(out_tensors_[0]->Data());
   auto channels = input->shape();
   prelu_param_->negtive_slope_ = reinterpret_cast<float *>(input1->Data());
-  prelu_param_->channel_num_ = channels.at(channels.size() - 1);
+  prelu_param_->channel_num_ = channels.at(1);
 
   auto ret = LiteBackendParallelLaunch(CaffePReluRun, this, prelu_param_->op_parameter_.thread_num_);
   if (ret != RET_OK) {

mindspore/lite/src/runtime/kernel/arm/nnacl/caffeprelu.c

@@ -27,7 +27,7 @@ void CaffePRelu(float *input, float *output, CaffePReluParameter *prelu_param_,
       output[i] = input[i];
     } else {
       if (!prelu_param_->channeShared) {
-        int temp = i % prelu_param_->channel_num_;
+        int temp = i / (prelu_param_->input_num_ / prelu_param_->channel_num_);
         output[i] = input[i] * prelu_param_->negtive_slope_[temp];
       } else {
         output[i] = input[i] * prelu_param_->negtive_slope_[0];