ocfs2: Compute metaecc for superblocks during online resize.

Online resize writes out the new superblock and its backups directly.
The metaecc data wasn't being recomputed.  Let's do that directly.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com&gt;[>
Cc: stable@kernel.org