PNP: add pnp_alloc_dev()

Add pnp_alloc_dev() to allocate a struct pnp_dev and fill in the
protocol, instance number, and initial PNP ID.  Now it is always
valid to use dev_printk() on any pnp_dev pointer.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Acked-By: Rene Herman <rene.herman@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/pnp/isapnp/core.c

@@ -409,18 +409,17 @@ static struct pnp_dev *__init isapnp_parse_device(struct pnp_card *card,
 	char id[8];
 
 	isapnp_peek(tmp, size);
-	dev = kzalloc(sizeof(struct pnp_dev), GFP_KERNEL);
-	if (!dev)
-		return NULL;
-	dev->number = number;
 	eisa_id = tmp[0] | tmp[1] << 8 | tmp[2] << 16 | tmp[3] << 24;
 	pnp_eisa_id_to_string(eisa_id, id);
-	pnp_add_id(dev, id);
+
+	dev = pnp_alloc_dev(&isapnp_protocol, number, id);
+	if (!dev)
+		return NULL;
+
 	dev->regs = tmp[4];
 	dev->card = card;
 	if (size > 5)
 		dev->regs |= tmp[5] << 8;
-	dev->protocol = &isapnp_protocol;
 	dev->capabilities |= PNP_CONFIGURABLE;
 	dev->capabilities |= PNP_READ;
 	dev->capabilities |= PNP_WRITE;