ocfs2/dlm: don't access beyond bitmap size

dlm->recovery_map is defined as
	unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];

We should treat O2NM_MAX_NODES as the bit map size in bits.
This patches fixes a bit operation that takes O2NM_MAX_NODES + 1 as bitmap size.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/dlm/dlmrecovery.c

@@ -463,7 +463,7 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm)
 	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
 		int bit;
 
-		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
+		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
 		if (bit >= O2NM_MAX_NODES || bit < 0)
 			dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
 		else