Remove const/non-const code duplication in CConfigurableDomains

Implement the non-const method of findConfigurableDomain by calling the const
version, as described in Effective C++ Item 3.

Change-Id: Ib7b58100dc817d02092299923edf2e6c7ce2f117
Signed-off-by: David Wagner <david.wagner@intel.com>
diff --git a/parameter/ConfigurableDomains.cpp b/parameter/ConfigurableDomains.cpp
index dd7ede3..8dff45a 100644
--- a/parameter/ConfigurableDomains.cpp
+++ b/parameter/ConfigurableDomains.cpp
@@ -566,17 +566,10 @@
 // Domain retrieval
 CConfigurableDomain* CConfigurableDomains::findConfigurableDomain(const string& strDomain, string& strError)
 {
-    // Find domain
-    CConfigurableDomain* pConfigurableDomain = static_cast<CConfigurableDomain*>(findChild(strDomain));
-
-    if (!pConfigurableDomain) {
-
-        strError = "Configurable domain " + strDomain + " not found";
-
-        return NULL;
-    }
-
-    return pConfigurableDomain;
+    // Call the const equivalent
+    return const_cast<CConfigurableDomain*>(
+        static_cast<const CConfigurableDomains*>(this)->findConfigurableDomain(strDomain, strError)
+        );
 }
 
 const CConfigurableDomain* CConfigurableDomains::findConfigurableDomain(const string& strDomain, string& strError) const