Fix warnings detected by Dialyzer

src/ejabberd_captcha.erl

@@ -310,12 +310,8 @@ create_captcha_x(SID, To, Lang, HeadEls, TailEls) ->
 	        ] ++ TailEls
 	      },
 	    Tref = erlang:send_after(?CAPTCHA_LIFETIME, ?MODULE, {remove_id, Id}),
-	    case ets:insert(captcha, #captcha{id=Id, key=Key, tref=Tref}) of
-		true ->
+	    ets:insert(captcha, #captcha{id=Id, key=Key, tref=Tref}),
 	    {ok, [Captcha, Data]};
-		_Err ->
-		    error
-	    end;
 	_ ->
 	    error
     end.

src/mod_register.erl

@@ -505,9 +505,7 @@ write_time({{Y,Mo,D},{H,Mi,S}}) ->
 
 process_xdata_submit(El) ->
     case exmpp_xml:get_element(El, x) of
-        false ->
-	    error;
-        Xdata ->
+        #xmlel{} = Xdata ->
             Fields = jlib:parse_xdata_submit(Xdata),
             case catch {proplists:get_value("username", Fields),
 			proplists:get_value("password", Fields)} of
@@ -515,7 +513,9 @@ process_xdata_submit(El) ->
 		    {ok, User, Pass};
 		_ ->
 		    error
-	    end
+	    end;
+        _ ->
+	    error
     end.
 
 is_strong_password(Server, Password) ->