tcp: fix debugging without cc stats (VPP-1547)

Change-Id: I376856fcadce570bb555064435f5876eefb2befa
Signed-off-by: Florin Coras <fcoras@cisco.com>
diff --git a/src/vnet/tcp/tcp_debug.h b/src/vnet/tcp/tcp_debug.h
index b848d34..cf07492 100755
--- a/src/vnet/tcp/tcp_debug.h
+++ b/src/vnet/tcp/tcp_debug.h
@@ -879,6 +879,7 @@
 }
 #else
 #define TCP_EVT_CC_STAT_HANDLER(_tc, ...)
+#define TCP_EVT_CC_STAT_PRINT(_tc)
 #endif
 
 /*