[qemu] Fix missing space in args.

Change-Id: I186395ab1848d43e9361dfde4a3e85518248b178
diff --git a/qemu/config.go b/qemu/config.go
index 0c8d6aa..6262e1c 100644
--- a/qemu/config.go
+++ b/qemu/config.go
@@ -158,7 +158,7 @@
 
 	invocation = append(invocation, "-kernel", cfg.Kernel)
 	invocation = append(invocation, "-initrd", cfg.Initrd)
-	invocation = append(invocation, "-object,iothread,id=iothread0")
+	invocation = append(invocation, "-object", "iothread,id=iothread0")
 
 	// TODO: maybe we should introduce Device interface with three different
 	// implementations: Drive, Netdev and ISADebugExit to cleanup the code