This patch reverts commit 7082a29c22 ("ARC: use ACCESS_ONCE in cmpxchg
loop").
It is not necessary to use READ_ONCE() because cmpxchg contains barrier. We
can get it from commit d57f727264 ("ARC: add compiler barrier to LLSC
based cmpxchg").
Signed-off-by: Bang Li <libang.linuxer@gmail.com>
Signed-off-by: Vineet Gupta <vgupta@kernel.org>
c6ed4d84a2