In the recipe of tcp-wrappers, setting the variable of FILES_tcp-wrappers is not working. Since it would be overwritten by FILES_${PN}. Besides, ${sbindir} should be included in the package tcp-wrappers, not ${bindir} since do_install install all the executables into ${sbindir}.
Patch sent out for review & merge http://git.yoctoproject.org/cgit.cgi/poky-contrib/commit/?h=llu/ml2&id=70399181518329ce158a37400198c5f4dcb92e0f
Fixed in master with http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=8c9fe92aa17ebc7b621e57fbe20d0dbe09395d99
Verified in patch http://git.yoctoproject.org/cgit.cgi/poky/commit/?id=8c9fe92aa17ebc7b621e57fbe20d0dbe09395d99