Really test the circular buffer
Really test the circular buffer

We now reread the metadata after writing it and look for the
LV in the re-read data. Also, the test is tweaked so that it
actually does wrap around in the metadata area.

Signed-off-by: Jon Ludlam <e7e3380887a8f95cc9dc4f0d51dedc7e849a287a@citrix.com>

djs55/mirage-block-volume