This was lifted from libcrc [0] commit 7719e2112a9a960b1bba130d02bebdf58e8701f1
https://github.com/lammertb/libcrc
Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
Later version of bcache add different checksum types, and allow for superblocks
greater than 4k - skipping the checksum check (as in most other probes) is the
easiest solution.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>