!2154 fix profiling core dump when start profiling many times

Merge pull request !2154 from caifubi/fix-profiling-core-dump

mindspore/ccsrc/device/ascend/profiling/profiling_manager.cc

@@ -169,7 +169,7 @@ bool ProfilingManager::StartupProfiling(uint32_t device_id) {
   return true;
 }
 
-bool ProfilingManager::StopProfiling() const {
+bool ProfilingManager::StopProfiling() {
   MS_LOG(INFO) << "StopProfiling";
   if (!IsProfiling()) {
     MS_LOG(INFO) << "No need profiling. please export PROFILING_MODE and in train mode.";
@@ -184,8 +184,10 @@ bool ProfilingManager::StopProfiling() const {
     int result = ProfMgrStop(prof_handle_);
     if (result != 0) {
       MS_LOG(ERROR) << "ProfMgr stop return fail:" << result << ".";
+      prof_handle_ = nullptr;
       return false;
     }
+    prof_handle_ = nullptr;
   }
 
   return true;

mindspore/ccsrc/device/ascend/profiling/profiling_manager.h

@@ -39,7 +39,7 @@ class ProfilingManager {
   uint64_t GetJobId() const;
   bool ReportProfilingData(const map<uint32_t, string> &op_taskId_map) const;
   bool StartupProfiling(uint32_t device_id);
-  bool StopProfiling() const;
+  bool StopProfiling();
 
   inline bool IsProfiling() const {
     auto context = MsContext::GetInstance();