autofs: fix per-dentry timeout warning

autofs: fix per-dentry timeout warning

The check that determines if the message that warns about the per-dentry
timeout being greater than the super block timeout is not correct.

The initial value for this field is -1 and the type of the field is
unsigned long.

I could change the type to long but the message is in the wrong place
too, it should come after the timeout setting. So leave everything else
as it is and move the message and check the timeout is actually set
as an additional condition on issuing the message. Also fix the timeout
comparison.

Signed-off-by: Ian Kent <raven@themaw.net>
Link: https://patch.msgid.link/20251111060439.19593-2-raven@themaw.net
Signed-off-by: Christian Brauner <brauner@kernel.org>