UPSTREAM: f2fs: fix to update age extent correctly during truncation

nr_free may be less than len, we should update age extent cache
w/ range [fofs, len] rather than [fofs, nr_free].

Bug: 254441685
Fixes: 71644dff ("f2fs: add block_age-based extent cache")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit 8c0ed062)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I86dccb39f6e844b180046dc8560e3904700fb4e1