x86/xen: add missing \n at end of printk warning message

The message is missing a \n, add it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
index d37a0c7..90d1b83 100644
--- a/arch/x86/xen/platform-pci-unplug.c
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -61,7 +61,7 @@
 		}
 		break;
 	default:
-		printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
+		printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version\n");
 		return XEN_PLATFORM_ERR_PROTOCOL;
 	}