package/fio: fix license file

Sorry, I missed the changed filename.

Fixes
http://autobuild.buildroot.net/results/a35/a3596283632433831ea24c1d586f2067b034eb32/



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>