add info about bluestore to disklist

this patch adds information about bluestore/db/wal to the disklist,
and we set the journal count only when we have at least one journal on
the disk

also adapt the regression tests

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

test/disk_tests/cciss/disklist_expected.json

@@ -10,7 +10,6 @@
 	"model" : "LOGICAL_VOLUME",
 	"size" : 5120,
 	"wwn" : "0x0000000000000000",
-	"journals" : 0,
 	"gpt" : 1,
 	"devpath" : "/dev/cciss/c0d0"
     }