[PATCH] ocfs2 heartbeat: clean up bio submission code

As was already pointed out Mathieu Avila on Thu, 07 Sep 2006 03:15:25 -0700
that OCFS2 is expecting bio_add_page() to add pages to BIOs in an easily
predictable manner.

That is not true, especially for devices with own merge_bvec_fn().

Therefore OCFS2's heartbeat code is very likely to fail on such devices.

Move the bio_put() call into the bio's bi_end_io() function. This makes the
whole idea of trying to predict the behaviour of bio_add_page() unnecessary.
Removed compute_max_sectors() and o2hb_compute_request_limits().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>