vom: acl-l3: Fix pretty print for TCP mask and flags

Change-Id: If14d1b2d9b73de77321d94f10d48fa1bb04846f6
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
diff --git a/src/vpp-api/vom/acl_l3_rule.cpp b/src/vpp-api/vom/acl_l3_rule.cpp
index 2b850af..6a9383a 100644
--- a/src/vpp-api/vom/acl_l3_rule.cpp
+++ b/src/vpp-api/vom/acl_l3_rule.cpp
@@ -69,8 +69,8 @@
     << " srcportto: " << m_srcport_or_icmptype_last
     << " dstportfrom:" << m_dstport_or_icmpcode_first
     << " dstportto:" << m_dstport_or_icmpcode_last
-    << " tcpflagmask:" << m_tcp_flags_mask
-    << " tcpflagvalue:" << m_tcp_flags_value << "]";
+    << " tcpflagmask:" << std::to_string(m_tcp_flags_mask)
+    << " tcpflagvalue:" << std::to_string(m_tcp_flags_value) << "]";
 
   return (s.str());
 }