md: fix super_offset endianness in super_1_rdev_size_change

BugLink: http://bugs.launchpad.net/bugs/1705238

commit 3fb632e4 upstream.

The sb->super_offset should be big-endian, but the rdev->sb_start is in
host byte order, so fix this by adding cpu_to_le64.
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/md/md.c

@@ -1866,7 +1866,7 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 	}
 	sb = page_address(rdev->sb_page);
 	sb->data_size = cpu_to_le64(num_sectors);
-	sb->super_offset = rdev->sb_start;
+	sb->super_offset = cpu_to_le64(rdev->sb_start);
 	sb->sb_csum = calc_sb_1_csum(sb);
 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
 		       rdev->sb_page);