Avoid nonconst memmodels in libitm's local outdated copy of <atomic> too

This avoids warnings in libitm for non constant memory models,
fixing the bootstrap with -Werror

Passed bootstrap and test on x86_64-linux.

libitm/:

2013-03-23  Andi Kleen  <andi@my.domain.org>

	* local_atomic (__always_inline): Add.
	(__calculate_memory_order, atomic_thread_fence,
	 atomic_signal_fence, test_and_set, clear, store, load,
         exchange, compare_exchange_weak, compare_exchange_strong,
         fetch_add, fetch_sub, fetch_and, fetch_or, fetch_xor):
	Add __always_inline to force inlining.

From-SVN: r197018