fuse: fix time_to_jiffies nsec sanity check

fuse: fix time_to_jiffies nsec sanity check

Commit bcb6f6d2b9c2 ("fuse: use timespec64") introduced clamped nsec values
in time_to_jiffies but used the max of nsec and NSEC_PER_SEC - 1 instead of
the min. Because of this, dentries would stay in the cache longer than
requested and go stale in scenarios that relied on their timely eviction.

Fixes: bcb6f6d2b9c2 ("fuse: use timespec64")
Signed-off-by: David Sheets <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>
Cc: <[email protected]> # 4.9