When runqemu tries to determine the MACHINE variable from a
kernel or vmdk filename that doesn't contain any known machine
name, the variable gets set to the filename. It should remain
unset and cause an error.
[YOCTO #2890]
(From OE-Core rev: 22c0668d9e0a22c095d78bab7b45ef4f803dd0d1)
Signed-off-by: Mihai Prica <mihai.prica@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>