erofs-utils: mkfs: fix extent-based deduplication

- `pstart` should be `erofs_off_t` instead of `erofs_blk_t`, otherwise,
  its upper 32 bits may be truncated;

- If it falls back to uncompressed inodes due to insufficient
  space savings, dedupe-ext records should also be revoked.

Reported-by: Axel Fontaine <axel@axelfontaine.com>
Fixes: cf04b8b78f09 ("erofs-utils: mkfs: implement extent-based deduplication")
Closes: https://github.com/erofs/erofs-utils/issues/23
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250711174324.3428957-1-hsiangkao@linux.alibaba.com
3 files changed