ceph: fix crush map update decoding

If the incremental osdmap has a new crush map, advance the position after
decoding so that we can parse the rest of the osdmap properly.

Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index ddc656f..50ce64e 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -707,6 +707,7 @@
 		newcrush = crush_decode(*p, min(*p+len, end));
 		if (IS_ERR(newcrush))
 			return ERR_CAST(newcrush);
+		*p += len;
 	}
 
 	/* new flags? */