xen: sysfs: fix build warning.

Define PRI macros for xen_ulong_t and xen_pfn_t and use to fix:
drivers/xen/sys-hypervisor.c:288:4: warning: format '%lx' expects argument of type 'long unsigned int', but argument 3 has type 'xen_ulong_t' [-Wformat]

Ideally this would use PRIx64 on ARM but these (or equivalent) don't
seem to be available in the kernel.

Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c
index 66a0a14..96453f8 100644
--- a/drivers/xen/sys-hypervisor.c
+++ b/drivers/xen/sys-hypervisor.c
@@ -285,7 +285,8 @@
 		ret = HYPERVISOR_xen_version(XENVER_platform_parameters,
 					     parms);
 		if (!ret)
-			ret = sprintf(buffer, "%lx\n", parms->virt_start);
+			ret = sprintf(buffer, "%"PRI_xen_ulong"\n",
+				      parms->virt_start);
 		kfree(parms);
 	}