Use a less misleading name for the code that sets up the main thread.

Change-Id: I50c1b0a3b633cf8bc40a6bd86f12adb6b91e2888

libc/bionic/libc_init_static.cpp

@@ -90,7 +90,7 @@ __noreturn void __libc_init(void* raw_args,
                             int (*slingshot)(int, char**, char**),
                             structors_array_t const * const structors) {
   KernelArgumentBlock args(raw_args);
-  __libc_init_tls(args);
+  __libc_init_main_thread(args);
   __libc_init_AT_SECURE(args);
   __libc_init_common(args);