Slim down `common.hpp`

Change-Id: Ic9843a1b9ffc5b5b1fa6062c8250ba28c6aaa898
diff --git a/tools/ping/client/ping.cpp b/tools/ping/client/ping.cpp
index cacd845..3bc5693 100644
--- a/tools/ping/client/ping.cpp
+++ b/tools/ping/client/ping.cpp
@@ -61,9 +61,9 @@
 
   auto now = time::steady_clock::now();
   m_face.expressInterest(interest,
-    [=, seq = m_nextSeq] (auto&&...) { onData(seq, now); },
-    [=, seq = m_nextSeq] (auto&&, const auto& nack) { onNack(seq, now, nack); },
-    [=, seq = m_nextSeq] (auto&&...) { onTimeout(seq); });
+    [this, seq = m_nextSeq, now] (auto&&...) { onData(seq, now); },
+    [this, seq = m_nextSeq, now] (auto&&, const auto& nack) { onNack(seq, now, nack); },
+    [this, seq = m_nextSeq] (auto&&...) { onTimeout(seq); });
 
   ++m_nSent;
   ++m_nextSeq;