ocfs2: Convert to use bdev_open_by_dev()

Convert ocfs2 heartbeat code to use bdev_open_by_dev() and pass the
handle around.

CC: Joseph Qi <joseph.qi@linux.alibaba.com>
CC: ocfs2-devel@oss.oracle.com
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20230927093442.25915-26-jack@suse.cz


Signed-off-by: Christian Brauner <brauner@kernel.org>