cpu: do not use object_delete

CPUs are never added to the composition tree, so delete is achieved
simply by removing the last references to them.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/target-sparc/cpu.c b/target-sparc/cpu.c
index f404aa8..4bc1afc 100644
--- a/target-sparc/cpu.c
+++ b/target-sparc/cpu.c
@@ -119,7 +119,7 @@
     }
 
     if (cpu_sparc_register(env, cpu_model) < 0) {
-        object_delete(OBJECT(cpu));
+        object_unref(OBJECT(cpu));
         return NULL;
     }
     qemu_init_vcpu(env);