illumos-lx: Fix test so it works under virtualization

illumos-lx: Fix test so it works under virtualization

Tests need to provide dummy sbin/virt-what-cpuid-helper, dmidecode and
uname.  This ensures that if we are running the test suite under (eg)
KVM, that virt-what doesn't discover this.

The failure was:

./test.sh: test failed because output did not match expected
Expected output was:
----------------------------------------
illumos-lx
----------------------------------------
But the actual output of the program was:
----------------------------------------
illumos-lx
kvm
----------------------------------------

Fixes: commit 763cf1b1123136751b71f475610c5ac1eeaba0ad