f2fs: update from arter97
Revert "arm: use RWSEM_XCHGADD_ALGORITHM part2 thx Ezekeel"

This reverts commit b3efe831d2e1138d0e9fabae2b6a7af1032a646f.
Revert "arm: use RWSEM_XCHGADD_ALGORITHM"

This reverts commit 9aab085ace0544f8a142b0eb093d896ebbe0db40.
arm: use RWSEM_XCHGADD_ALGORITHM
arm: use RWSEM_XCHGADD_ALGORITHM part2 thx Ezekeel