First of all lengths should be compared after checking all blocks for
being good/bad. It's because requested length may differ from a final
one if there were some bad blocks.
Secondly it makes sense to also compare crc32 since we already have a
new one calculated.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 82498a7f7aa86ad0e93ef60d50dccaa0a9549e4c)