BACKPORT: f2fs: introduce update_sit_entry_for_release/alloc()

No logical changes, just for cleanliness.

Bug: 394006856
Change-Id: I4dddab6be974476879af46cda814dee2223ed21d
Signed-off-by: Yi Sun <yi.sun@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Dylan: Resolved minor conflict in fs/f2fs/segment.c ]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit 66baee2b)