It is odd that we inform user that, for example, his current working
directory is not kernel root, when, in face, we mean qemu root.

Replace that and few other similar odd user messages.

Signed-off-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Message-Id: <20200620133207.26849-3-aleksandar.qemu.devel@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>