Instead of checksumming each field as it is added to the block, just
checksum each block before it is written.  This is simpler, and also
much more efficient.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221106224841.279231-8-ebiggers@kernel.org


Signed-off-by: Theodore Ts'o <tytso@mit.edu>