fs: remove simple_nosetlease()

fs: remove simple_nosetlease()

Setting ->setlease() to a NULL pointer now has the same effect as
setting it to simple_nosetlease(). Remove all of the setlease
file_operations that are set to simple_nosetlease, and the function
itself.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260108-setlease-6-20-v1-24-ea4dec9b67fa@kernel.org
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>