Change the signature of the command handler functions.

Resolves openbmc/openbmc#857

Change-Id: I0b7ca6665dd89629838a238d77aff67fec1818c7
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/command/rakp34.cpp b/command/rakp34.cpp
index cd455cd..95b8af7 100644
--- a/command/rakp34.cpp
+++ b/command/rakp34.cpp
@@ -53,13 +53,13 @@
     }
 }
 
-std::vector<uint8_t> RAKP34(std::vector<uint8_t>& inPayload,
+std::vector<uint8_t> RAKP34(const std::vector<uint8_t>& inPayload,
                             const message::Handler& handler)
 {
     std::cout << ">> RAKP34\n";
 
     std::vector<uint8_t> outPayload(sizeof(RAKP4response));
-    auto request = reinterpret_cast<RAKP3request*>(inPayload.data());
+    auto request = reinterpret_cast<const RAKP3request*>(inPayload.data());
     auto response = reinterpret_cast<RAKP4response*>(outPayload.data());
 
     // Check if the RAKP3 Payload Length is as expected