encoding: remove duplicate buf() and get() methods from Buffer class

Change-Id: If885d4199d6c9df9b9b46664c3641c9a14a77eab
diff --git a/src/security/verification-helpers.cpp b/src/security/verification-helpers.cpp
index 1d22373..8c42937 100644
--- a/src/security/verification-helpers.cpp
+++ b/src/security/verification-helpers.cpp
@@ -155,13 +155,13 @@
 bool
 verifySignature(const Data& data, const pib::Key& key)
 {
-  return verifySignature(parse(data), key.getPublicKey().buf(), key.getPublicKey().size());
+  return verifySignature(parse(data), key.getPublicKey().data(), key.getPublicKey().size());
 }
 
 bool
 verifySignature(const Interest& interest, const pib::Key& key)
 {
-  return verifySignature(parse(interest), key.getPublicKey().buf(), key.getPublicKey().size());
+  return verifySignature(parse(interest), key.getPublicKey().data(), key.getPublicKey().size());
 }
 
 bool
@@ -209,7 +209,7 @@
     return false;
 
   // constant-time buffer comparison to mitigate timing attacks
-  return CRYPTO_memcmp(result->buf(), digest, digestLen) == 0;
+  return CRYPTO_memcmp(result->data(), digest, digestLen) == 0;
 }
 
 bool