explicit use of std::vector instead of buffer/Buffer

There were several scoped 'using buffer = std::vector<uint8_t>;' in
header files. This consolidates the code base to use
std::vector<uint8_t> instead of buffer or Buffer. This makes the code
easier to read and debug.

Change-Id: I918a0f6ca9b8e4b9d331175dccff45cbf4c8379d
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/test/cipher.cpp b/test/cipher.cpp
index 84929d6..f10c8a0 100644
--- a/test/cipher.cpp
+++ b/test/cipher.cpp
@@ -51,7 +51,7 @@
     }
 
     mdLen = 0;
-    cipher::integrity::Buffer output(SHA_DIGEST_LENGTH);
+    std::vector<uint8_t> output(SHA_DIGEST_LENGTH);
     size_t length = packet.size() - message::parser::RMCP_SESSION_HEADER_SIZE;
 
     if (HMAC(EVP_sha1(), K1.data(), K1.size(),
@@ -102,7 +102,7 @@
     }
 
     mdLen = 0;
-    cipher::integrity::Buffer output(SHA_DIGEST_LENGTH);
+    std::vector<uint8_t> output(SHA_DIGEST_LENGTH);
     size_t length = packet.size() - message::parser::RMCP_SESSION_HEADER_SIZE;
 
     if (HMAC(EVP_sha1(), K1.data(), K1.size(),