Only unpack udev's testdata right before executing the tests and cleanup
afterwards.
udev's testsuite can be used by ptest. However currently the testdata against
which its functionality is tested is installed in the sysroot at udev install
time.
If the sysroot is used with qemu the testdata makes qemu entering an infinite
loop.
http://lists.openembedded.org/pipermail/openembedded-core/2014-September/097098.html
This has already been fixed for the systemd udev flavour.
https://bugzilla.yoctoproject.org/show_bug.cgi?id=5664
Signed-off-by: Max Krummenacher <max.oss.09@gmail.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
