rt2x00: make csr_cache and csr_addr an union

The csr_cache and csr_addr pointers are both the same size
and they are never used both by the same driver. This makes
them a nice candidate for an union.
We could merge into 1 pointer, but that would either upset sparse,
or require a lot of __force casts.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00pci.c b/drivers/net/wireless/rt2x00/rt2x00pci.c
index 238f1c1..b8c6a8c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00pci.c
+++ b/drivers/net/wireless/rt2x00/rt2x00pci.c
@@ -350,9 +350,9 @@
 	kfree(rt2x00dev->eeprom);
 	rt2x00dev->eeprom = NULL;
 
-	if (rt2x00dev->csr_addr) {
-		iounmap(rt2x00dev->csr_addr);
-		rt2x00dev->csr_addr = NULL;
+	if (rt2x00dev->csr.base) {
+		iounmap(rt2x00dev->csr.base);
+		rt2x00dev->csr.base = NULL;
 	}
 }
 
@@ -360,9 +360,9 @@
 {
 	struct pci_dev *pci_dev = rt2x00dev_pci(rt2x00dev);
 
-	rt2x00dev->csr_addr = ioremap(pci_resource_start(pci_dev, 0),
+	rt2x00dev->csr.base = ioremap(pci_resource_start(pci_dev, 0),
 				      pci_resource_len(pci_dev, 0));
-	if (!rt2x00dev->csr_addr)
+	if (!rt2x00dev->csr.base)
 		goto exit;
 
 	rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);