resolve a segfault bug when env var not set; remove startup_kernel_loader class

src/program_state.cpp

@@ -516,16 +516,11 @@ hsa_executable_t load_executable(const string& file, hsa_executable_t executable
 // HIP startup kernel loader logic
 // When enabled HIP_STARTUP_LOADER, HIP will load the kernels and setup
 // the function symbol map on program startup
-class startup_kernel_loader {
-   private:
-    startup_kernel_loader() { functions(); }
-    startup_kernel_loader(const startup_kernel_loader&) = delete;
-    startup_kernel_loader& operator=(const startup_kernel_loader&) = delete;
-    static startup_kernel_loader skl;
-};
-
 extern "C" void __attribute__((constructor)) __startup_kernel_loader_init() {
-    if (atoi(std::getenv("HIP_STARTUP_LOADER")) == 1) functions();
+    int hip_startup_loader=0;
+    if (std::getenv("HIP_STARTUP_LOADER"))
+        hip_startup_loader = atoi(std::getenv("HIP_STARTUP_LOADER"));
+    if (hip_startup_loader) functions();
 }
 
 extern "C" void __attribute__((destructor)) __startup_kernel_loader_fini() {