fuse: make sure dentry is evicted if stale

fuse: make sure dentry is evicted if stale

d_dispose_if_unused() may find the dentry with a positive refcount, in
which case it won't be put on the dispose list even though it has already
timed out.

"Reinstall" the d_delete() callback, which was optimized out in
fuse_dentry_settime().  This will result in the dentry being evicted as
soon as the refcount hits zero.

Fixes: ab84ad597386 ("fuse: new work queue to periodically invalidate expired dentries")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Link: https://patch.msgid.link/20260114145344.468856-3-mszeredi@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>