8043770: File leak in MemNotifyThread::start() in hotspot.src.os.linux.vm.os_linux.cpp

Fixed by removing all code related to LowMemoryProtection, which removed offending code.

Reviewed-by: dholmes, minqi

hotspot/src/os/bsd/vm/os_bsd.cpp

@@ -3635,9 +3635,6 @@ jint os::init_2(void) {
   return JNI_OK;
 }
 
-// this is called at the end of vm_initialization
-void os::init_3(void) { }
-
 // Mark the polling page as unreadable
 void os::make_polling_page_unreadable(void) {
   if (!guard_memory((char*)_polling_page, Bsd::page_size())) {