ceph: make CRUSH hash function a bucket property

Make the integer hash function a property of the bucket it is used on.  This
allows us to gracefully add support for new hash functions without starting
from scatch.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index 6847827..8c994c7 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -210,7 +210,8 @@
 		ceph_decode_need(p, end, 4*sizeof(u32), bad);
 		b->id = ceph_decode_32(p);
 		b->type = ceph_decode_16(p);
-		b->alg = ceph_decode_16(p);
+		b->alg = ceph_decode_8(p);
+		b->hash = ceph_decode_8(p);
 		b->weight = ceph_decode_32(p);
 		b->size = ceph_decode_32(p);