KVM: fix assigned_device_enable_host_msix error handling

Free IRQ's and disable MSIX upon failure.

Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Jing Zhang <zj.barak@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

virt/kvm/assigned-dev.c

@@ -316,12 +316,16 @@ static int assigned_device_enable_host_msix(struct kvm *kvm,
 				kvm_assigned_dev_intr, 0,
 				"kvm_assigned_msix_device",
 				(void *)dev);
-		/* FIXME: free requested_irq's on failure */
 		if (r)
-			return r;
+			goto err;
 	}
 
 	return 0;
+err:
+	for (i -= 1; i >= 0; i--)
+		free_irq(dev->host_msix_entries[i].vector, (void *)dev);
+	pci_disable_msix(dev->dev);
+	return r;
 }
 
 #endif