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/pcie_i2c.hpp b/pcie_i2c.hpp
index ef89865..556cd23 100644
--- a/pcie_i2c.hpp
+++ b/pcie_i2c.hpp
@@ -12,14 +12,12 @@
 //  Handle the pcie slot count command.
 //  Sys can query the number of pcie slots.
 ipmi_ret_t pcieSlotCount(const uint8_t* reqBuf, uint8_t* replyBuf,
-                         size_t* dataLen,
-                         HandlerInterface* handler = &handlerImpl);
+                         size_t* dataLen, HandlerInterface* handler);
 
 // Handle the pcie slot to i2c bus mapping command.
 // Sys can query which i2c bus is routed to which pcie slot.
 ipmi_ret_t pcieSlotI2cBusMapping(const uint8_t* reqBuf, uint8_t* replyBuf,
-                                 size_t* dataLen,
-                                 HandlerInterface* handler = &handlerImpl);
+                                 size_t* dataLen, HandlerInterface* handler);
 
 } // namespace ipmi
 } // namespace google