[POWERPC] Convert pci and eeh code to of_device_is_available

A couple of places are duplicating the function of
of_device_is_available; convert them to use it.

Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 9eb539e..550b2f7d 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -945,7 +945,6 @@
 	unsigned int rets[3];
 	struct eeh_early_enable_info *info = data;
 	int ret;
-	const char *status = of_get_property(dn, "status", NULL);
 	const u32 *class_code = of_get_property(dn, "class-code", NULL);
 	const u32 *vendor_id = of_get_property(dn, "vendor-id", NULL);
 	const u32 *device_id = of_get_property(dn, "device-id", NULL);
@@ -959,8 +958,8 @@
 	pdn->eeh_freeze_count = 0;
 	pdn->eeh_false_positives = 0;
 
-	if (status && strncmp(status, "ok", 2) != 0)
-		return NULL;	/* ignore devices with bad status */
+	if (!of_device_is_available(dn))
+		return NULL;
 
 	/* Ignore bad nodes. */
 	if (!class_code || !vendor_id || !device_id)