File magic_ioport_compat.patch of Package xen

Make our PV drivers work  with older hosts that do not recognize the new PV driver protocol. 

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>

Index: xen-4.0.1-testing/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
===================================================================
--- xen-4.0.1-testing.orig/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
+++ xen-4.0.1-testing/unmodified_drivers/linux-2.6/platform-pci/platform-pci.c
@@ -320,7 +320,10 @@ static int check_platform_magic(struct d
 
 	if (magic != XEN_IOPORT_MAGIC_VAL) {
 		err = "unrecognised magic value";
-		goto no_dev;
+		/*
+		 * Older backend; just return 0 to be compatible.
+		 */
+		return 0;
 	}
 
 	protocol = inb(XEN_IOPORT_PROTOVER);