sdbus++: interface: move basic constructor inline

This saves 100k out of the libphosphor_dbus.so on x86.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Iadd57bdb6517ac3dcb92c2165d9913f622511c6e
diff --git a/tools/sdbusplus/templates/interface.server.cpp.mako b/tools/sdbusplus/templates/interface.server.cpp.mako
index fe91780..6edc845 100644
--- a/tools/sdbusplus/templates/interface.server.cpp.mako
+++ b/tools/sdbusplus/templates/interface.server.cpp.mako
@@ -14,19 +14,10 @@
 <%
     namespaces = interface.name.split('.')
     classname = namespaces.pop()
-
-    def interface_instance():
-        return "_".join(interface.name.split('.') + ['interface'])
 %>
 namespace sdbusplus::${interface.cppNamespace()}
 {
 
-${classname}::${classname}(bus_t& bus, const char* path)
-        : _${interface_instance()}(
-                bus, path, interface, _vtable, this), _intf(bus.getInterface())
-{
-}
-
     % if interface.properties:
 ${classname}::${classname}(bus_t& bus, const char* path,
                            const std::map<std::string, PropertiesVariant>& vals,
diff --git a/tools/sdbusplus/templates/interface.server.hpp.mako b/tools/sdbusplus/templates/interface.server.hpp.mako
index 771c6ac..a98a3c4 100644
--- a/tools/sdbusplus/templates/interface.server.hpp.mako
+++ b/tools/sdbusplus/templates/interface.server.hpp.mako
@@ -18,6 +18,9 @@
     def setOfPropertyTypes():
         return set(p.cppTypeParam(interface.name) for p in
                    interface.properties);
+
+    def interface_instance():
+        return "_".join(interface.name.split('.') + ['interface'])
 %>
 
 namespace sdbusplus::${interface.cppNamespace()}
@@ -46,7 +49,11 @@
          *  @param[in] bus - Bus to attach to.
          *  @param[in] path - Path to attach at.
          */
-        ${classname}(bus_t& bus, const char* path);
+        ${classname}(bus_t& bus, const char* path) :
+            _${interface_instance()}(
+                bus, path, interface, _vtable, this),
+            _intf(bus.getInterface()) {}
+
 
     % for e in interface.enums:
         enum class ${e.name}