!11750 fix resize_base bug & fix fp16subgraph bug when const-input gather exist

From: @hangangqiang
Reviewed-by: @zhanghaibo5,@ddwsky
Signed-off-by: @zhanghaibo5

mindspore/lite/src/runtime/kernel/arm/base/resize_base.cc

@@ -62,7 +62,7 @@ int ResizeBaseCPUKernel::CheckParameters() {
       MS_LOG(INFO) << "Out shape is not assigned";
       const_shape_ = false;
     } else {
-      auto ret = CalculateNewHeightWidth();
+      auto ret = CalculateLinearNewHeightWidth();
       if (ret != RET_OK) {
         return ret;
       }
@@ -78,7 +78,10 @@ int ResizeBaseCPUKernel::CheckParameters() {
   return RET_OK;
 }
 
-int ResizeBaseCPUKernel::CalculateNewHeightWidth() {
+int ResizeBaseCPUKernel::CalculateLinearNewHeightWidth() {
+  if (method_ != static_cast<int>(schema::ResizeMethod_LINEAR)) {
+    return RET_OK;
+  }
   if (in_tensors_.size() != 2) {
     return RET_ERROR;
   }

mindspore/lite/src/runtime/kernel/arm/base/resize_base.h

@@ -47,7 +47,7 @@ class ResizeBaseCPUKernel : public LiteKernel {
  private:
   int CheckParameters();
   int CheckInputsOuputs();
-  int CalculateNewHeightWidth();
+  int CalculateLinearNewHeightWidth();
 };
 }  // namespace mindspore::kernel
 

mindspore/lite/src/tensor.cc

@@ -282,8 +282,7 @@ int Tensor::set_root_tensor(Tensor *tensor) {
     return RET_OK;
   }
   if (this->root_tensor_ == nullptr) {
-    MS_LOG(ERROR) << "root tensor is nullptr";
-    return RET_NULL_PTR;
+    return RET_OK;
   }
   this->shape_ = this->root_tensor_->shape_;
   this->format_ = this->root_tensor_->format_;