[OpenMP][libomptarget] Minor fix in x86_64 plugin

[hbae]

Summary

Call to remove() was passing invalid address for the file name.

[grokos]

Good catch, LGTM!

openmp/libomptarget/plugins/generic-elf-64bit/src/rtl.cpp

 //===----------------------------------------------------------------------===//
 
 #include <cassert>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <dlfcn.h>
 #include <ffi.h>
 #include <gelf.h>
 #include <link.h>
 #include <list>
 #include <string>
 #include <vector>
 
 #include "Debug.h"
 #include "omptargetplugin.h"
 
 #ifndef TARGET_NAME
 #define TARGET_NAME Generic ELF - 64bit
 #endif
 #define DEBUG_PREFIX "TARGET " GETNAME(TARGET_NAME) " RTL"
 
 #ifndef TARGET_ELF_ID
 #define TARGET_ELF_ID 0
 #endif
 
 #include "elf_common.h"
 
 #define NUMBER_OF_DEVICES 4
 #define OFFLOADSECTIONNAME "omp_offloading_entries"
 
 /// Array of Dynamic libraries loaded for this target.
 struct DynLibTy {
-  char *FileName;
+  std::string FileName;
   void *Handle;
 };
 
 /// Keep entries table per device.
 struct FuncOrGblEntryTy {
   __tgt_target_table Table;
 };
 
public:
 
   RTLDeviceInfoTy(int32_t num_devices) { FuncGblEntries.resize(num_devices); }
 
   ~RTLDeviceInfoTy() {
     // Close dynamic libraries
     for (auto &lib : DynLibs) {
       if (lib.Handle) {
         dlclose(lib.Handle);
-        remove(lib.FileName);
+        remove(lib.FileName.c_str());
       }
     }
   }
 };
 
 static RTLDeviceInfoTy DeviceInfo(NUMBER_OF_DEVICES);
 
 #ifdef __cplusplus