xen: relax signature check

Some versions of Xen 3.x set their magic number to "xen-3.[12]", so relax the test to match them.

[ Linus: Please apply for 2.6.24. Thanks - J ]

---
 arch/x86/xen/enlighten.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

===================================================================

@@ -1131,7 +1131,7 @@ asmlinkage void __init xen_start_kernel(
 	if (!xen_start_info)
 		return;
 
-	BUG_ON(memcmp(xen_start_info->magic, "xen-3.0", 7) != 0);
+	BUG_ON(memcmp(xen_start_info->magic, "xen-3", 5) != 0);
 
 	/* Install Xen paravirt ops */
 	pv_info = xen_info;