split out handler implementation from interface

Split out the handler object definition from the interface and drop the
default parameters.

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: Ie8c9dbf7881bbe6b5af3596a60430e3b3d573762
diff --git a/entity_name.hpp b/entity_name.hpp
index c04b996..5ed442b 100644
--- a/entity_name.hpp
+++ b/entity_name.hpp
@@ -12,8 +12,7 @@
 // Handle the "entity id:entity instance" to entity name mapping command.
 // Sys can query the entity name for a particular "entity id:entity instance".
 ipmi_ret_t getEntityName(const uint8_t* reqBuf, uint8_t* replyBuf,
-                         size_t* dataLen,
-                         HandlerInterface* handler = &handlerImpl);
+                         size_t* dataLen, HandlerInterface* handler);
 
 } // namespace ipmi
 } // namespace google