ocfs2: fix build for OCFS2_FS_STATS not enabled

When CONFIG_OCFS2_FS_STATS is not enabled:

fs/ocfs2/cluster/tcp.c:1254: error: implicit declaration of function 'o2net_update_recv_stats'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc:	Mark Fasheh <mfasheh@suse.com>
Cc:	Joel Becker <joel.becker@oracle.com>
Cc:	ocfs2-devel@oss.oracle.com
Signed-off-by: Joel Becker <joel.becker@oracle.com>
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
index bc23095..3b11cb1 100644
--- a/fs/ocfs2/cluster/tcp.c
+++ b/fs/ocfs2/cluster/tcp.c
@@ -257,6 +257,8 @@
 
 # define o2net_update_send_stats(a, b)
 
+# define o2net_update_recv_stats(sc)
+
 #endif /* CONFIG_OCFS2_FS_STATS */
 
 static inline int o2net_reconnect_delay(void)