FROMGIT: erofs: simplify try_to_claim_pcluster()

simplify try_to_claim_pcluster() by directly using cmpxchg() here
(the retry loop caused more overhead.) Also, move the chain loop
detection in and rename it to z_erofs_try_to_claim_pcluster().

Link: https://lore.kernel.org/r/20201208095834.3133565-3-hsiangkao@redhat.com


Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

BUG=b:273658215
TEST=`tast run $DUT arc.Boot.vm`
TEST=`tast run $DUT arc.Playstore.vm`

(cherry picked from commit 43f037b6
 https://android.googlesource.com/kernel/common

 android13-5.10)
Change-Id: I1d818e7bcaaa7c4cec9b63d36e7295085da8a14e
Signed-off-by: Ryuichiro Chiba <chibar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/4444987


Reviewed-by: Suleiman Souhlal <suleiman@chromium.org>
Reviewed-by: Sean Paul <sean@poorly.run>