minikconf: print error entirely on stderr

While debugging an invalid configuration, I noticed that the clauses debug
ends up on stderr but the header ("The following clauses were found..."
ends up on stdout.  This makes the contents of meson-logs/meson-log.txt
a bit confusing.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
1 file changed