xfs_repair: update secondary superblocks after changing features

xfs_repair: update secondary superblocks after changing features

When we add features to an existing filesystem, make sure we update the
secondary superblocks to reflect the new geometry so that if we lose the
primary super in the future, repair will recover correctly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>