KVM: add missing misc_deregister() on error in kvm_init()

Add the missing misc_deregister() before return from kvm_init()
in the debugfs init error handling case.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NGleb Natapov <gleb@redhat.com>

virt/kvm/kvm_main.c

@@ -3181,6 +3181,7 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 
 out_undebugfs:
 	unregister_syscore_ops(&kvm_syscore_ops);
+	misc_deregister(&kvm_dev);
 out_unreg:
 	kvm_async_pf_deinit();
 out_free: