md: fix update super 1.0 on rdev size change

The superblock of version 1.0 doesn't get moved to the new position on a
device size change. This leads to a rdev without a superblock on a known
position, the raid can't be re-assembled.

The line was removed by mistake and is re-added by this patch.

Fixes: d9c0fa50 ("md: fix max sectors calculation for super 1.0")
Cc: stable@vger.kernel.org
Signed-off-by: Markus Hochholdinger <markus@hochholdinger.net>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>

drivers/md/md.c

@@ -2189,6 +2189,7 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 
 		if (!num_sectors || num_sectors > max_sectors)
 			num_sectors = max_sectors;
+		rdev->sb_start = sb_start;
 	}
 	sb = page_address(rdev->sb_page);
 	sb->data_size = cpu_to_le64(num_sectors);