Bug 795406 - Set up profile unlocker. r=bsmedberg

toolkit/xre/nsAppRunner.cpp

@@ -2220,7 +2220,7 @@ SelectProfile(nsIProfileLock* *aResult, nsIToolkitProfileService* aProfileSvc, n
       }
 
       nsCOMPtr<nsIProfileUnlocker> unlocker;
-      rv = profile->Lock(nullptr, aResult);
+      rv = profile->Lock(getter_AddRefs(unlocker), aResult);
       if (NS_SUCCEEDED(rv)) {
         if (aProfileName)
           aProfileName->Assign(nsDependentCString(arg));