This adds a missing endian conversion of checksum field in the super
block.  This fixes compatibility issue on big endian machines which will
come to surface after supporting recovery of super block.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>