Fix 'kill' test to actually test that the connection has

been killed.

mysql-test/r/kill.result

@@ -5,6 +5,12 @@ select ((@id := kill_id) - kill_id) from t1;
 ((@id := kill_id) - kill_id)
 0
 kill @id;
+select ((@id := kill_id) - kill_id) from t1;
+((@id := kill_id) - kill_id)
+0
+select @id != connection_id();
+@id != connection_id()
+1
 select 4;
 4
 4

mysql-test/t/kill.test

@@ -27,8 +27,9 @@ kill @id;
 --sleep 5
 # verify that con1 is doning a reconnect
 connection con1;
-ping
-ping
+--ping
+--ping
+select ((@id := kill_id) - kill_id) from t1; 
 select @id != connection_id();
 
 #make sure the server is still alive