Fix mysterious "mender: command not found" message in build logs.
Fix mysterious "mender: command not found" message in build logs.

Backticks are evaluated in Here documents, so switch to quotes.

Signed-off-by: Kristian Amlie <505e66ae45028a0596c853559221f0b72c1cee21@northern.tech>

mendersoftware/meta-mender-qemu