dieharder: fix link issue with inline function not declared static

dieharder: fix link issue with inline function not declared static

Fixes:

  http://autobuild.buildroot.net/results/b629754c6a820446ff38df8202ea1ed0041bc4ac
  http://autobuild.buildroot.net/results/e02325e06866618d9d3ee90600dc3326465c56a1
  http://autobuild.buildroot.net/results/c1db73dcb25ea1db4be0f9d6ce2bf2d02f5bd5bb
  http://autobuild.buildroot.net/results/bd93120ee7cbfeb4fe7cbcd7f845f131743caf05
  http://autobuild.buildroot.net/results/273ba504de31bc17fd41e91ee5d6c0b34797a4f9
  http://autobuild.buildroot.net/results/37920b26f9c4853a0d620eb4a33b50b53e548888
  http://autobuild.buildroot.net/results/ee668405ed234fbbd644a01d49e8d9d41d216cf6
  http://autobuild.buildroot.net/results/5b76d62ad03d0cbe483792b32ea14ce7d7432983
  http://autobuild.buildroot.net/results/cf08d42be8fcb659d59288e2cedf3f18b660e8a6
  http://autobuild.buildroot.net/results/e1309fd2eea5daf854f4314b92ec441092239cd5

Signed-off-by: Julien Viard de Galbert <julien@vdg.name>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>