!3656 modify the wrong word of memory pool

Merge pull request !3656 from limingqi107/master

mindspore/ccsrc/backend/optimizer/mem_reuse/mem_dynamic_allocator.cc

@@ -191,7 +191,8 @@ void DynamicMemPoolBestFit::FreeTensorMem(const DeviceMemPtr device_addr) {
   MS_EXCEPTION_IF_NULL(device_addr);
   auto mem_block = FindMemBlock(device_addr);
   if (mem_block == nullptr) {
-    MS_LOG(WARNING) << "Can't find the mem_block of the device address[" << device_addr << "].";
+    // May be destory the memory pool first, then destory the address, so this is normal case.
+    MS_LOG(DEBUG) << "Can't find the mem_block of the device address[" << device_addr << "].";
     return;
   }
   CombineMemBuf(mem_block, device_addr);
@@ -262,7 +263,7 @@ void DynamicMemPoolBestFit::EraseIdleMemBuf(size_t size, const DeviceMemPtr devi
 }
 
 void DynamicMemPoolBestFit::ReleaseDeviceRes() {
-  MS_LOG(INFO) << "The dynamic memmory pool total size is " << total_mem_statistics_ << ", total used size is "
+  MS_LOG(INFO) << "The dynamic memory pool total size is " << total_mem_statistics_ << ", total used size is "
                << total_used_mem_statistics_ << ", used peak size is " << used_mem_peak_statistics_ << ".";
   for (auto iter = global_mem_block_list_.begin(); iter != global_mem_block_list_.end(); ++iter) {
     auto device_addr = (*iter)->device_addr();