Switch to using AT_RANDOM for the stack guards.

Bug: 7959813
Change-Id: I8db4b8912ba649bfe668c6f22aa44690ddd401a2

libc/bionic/libc_init_static.cpp

@@ -87,9 +87,8 @@ __noreturn void __libc_init(void* raw_args,
                             void (*onexit)(void),
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
-  __libc_init_tls(NULL);
-
   KernelArgumentBlock args(raw_args);
+  __libc_init_tls(args);
   __libc_init_common(args);
 
   apply_gnu_relro();