x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE

commit 78bff1c8 ("x86/ticketlock: Fix spin_unlock_wait() livelock")
introduced two additional ACCESS_ONCE cases in x86 spinlock.h.
Lets change those as well.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>

arch/x86/include/asm/spinlock.h

@@ -183,10 +183,10 @@ static __always_inline void arch_spin_lock_flags(arch_spinlock_t *lock,
 
 static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
 {
-	__ticket_t head = ACCESS_ONCE(lock->tickets.head);
+	__ticket_t head = READ_ONCE(lock->tickets.head);
 
 	for (;;) {
-		struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);
+		struct __raw_tickets tmp = READ_ONCE(lock->tickets);
 		/*
 		 * We need to check "unlocked" in a loop, tmp.head == head
 		 * can be false positive because of overflow.