libutempter: Fix license format QA error

Fix the following QA error:

,----
| WARNING: Recipe libutempter, LICENSE (GPLv2 GPLv2+ LGPLv2 MIT) has
|     invalid format, LICENSES must have operator "([&|() ])" between
|     them.
`----

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>