use mkstemp instead tempnam for temp file

tempnam has been marked as obsolete.

Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Change-Id: Ie64d9a351bf386da00a96ceff059f685e11f2cca


[ROCm/ROCR-Runtime commit: e82025bffa]

projects/rocr-runtime/runtime/hsa-runtime/libamdhsacode/amd_hsa_code_util.cpp

@@ -957,12 +957,8 @@ int OpenTempFile(const char* prefix)
 #ifdef _WIN32
     char dir[MAX_PATH+1];
     if (!GetTempPath(sizeof(dir), dir)) { return -1; }
-#else // _WIN32
-    char *dir = NULL;
-#endif // _WIN32
     char *name = _tempnam(dir, tname.c_str());
     if (!name) { return -1; }
-#ifdef _WIN32
     HANDLE h = CreateFile(
       name,
       GENERIC_READ | GENERIC_WRITE,
@@ -975,10 +971,10 @@ int OpenTempFile(const char* prefix)
     if (h == INVALID_HANDLE_VALUE) { continue; }
     return _open_osfhandle((intptr_t)h, 0);
 #else // _WIN32
-    int d = _open(name, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
-    if (d < 0) { free(name); continue; }
-    if (unlink(name) < 0) { free(name); _close(d); return -1; }
-    free(name);
+    tname += "XXXXXX";
+    int d = mkstemp((char*)tname.c_str());
+    if (d < 0) { continue; }
+    if (unlink(tname.c_str()) < 0) { _close(d); return -1; }
     return d;
 #endif // _WIN32
   }