qemu: Append nosplash to kernel arguments to stop plymouth from starting

The plymouth service starts when running a qemu/kvm guest, plymouth clears
the serial console during boot which in turn causes the host's shell to be
cleared. Add nosplash to the kernel argument to stop plymouth from
starting during the machine's boot.

This parameter is already present in the uml backend.

Fixes: #66
Signed-off-by: Christopher Obbard <chris.obbard@collabora.com>

backend_qemu.go

@@ -224,8 +224,11 @@ func (b qemuBackend) StartQemu(kvm bool) (bool, error) {
 	qemuargs = append(qemuargs, "-machine", qemuMachine.machine)
 	console := fmt.Sprintf("console=%s", qemuMachine.console)
 	kernelargs := []string{console, "panic=-1",
+		"nosplash",
 		"systemd.unit=fakemachine.service"}
 
+	kernelargs = append(kernelargs, "nosplash")
+
 	if m.showBoot {
 		// Create a character device representing our stdio
 		// file descriptors, and connect the emulated serial