log4j-slf4j-impl 2.6 is warning

when use log4j 2 2.6 ,
some class like private static final Logger log = LoggerFactory.getLogger(RestDispatcherServlet .class);
has warning :
WARN The Logger com.gentlesoft.framework.RestDispatcherServlet was created with the message factory org.apache.logging.log4j.spi.MessageFactory2Adapter@31bd1cd3 and is now requested with a null message factory (defaults to org.apache.logging.log4j.message.ParameterizedMessageFactory), which may create log events with unexpected formatting.

but some class no warning.

log4j 2.5 no this problem.