rt2x00: Move generic TX frame writing code into rt2x00queue

The write_tx_data functions in rt2x00pci and rt2x00usb have
a lot in common. This moves that duplicate code into
rt2x00queue_write_tx_frame().

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.h b/drivers/net/wireless/rt2x00/rt2x00pci.h
index 37c851e..87c4a0c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00pci.h
+++ b/drivers/net/wireless/rt2x00/rt2x00pci.h
@@ -87,11 +87,14 @@
 	memcpy_toio(rt2x00dev->csr.base + offset, value, length);
 }
 
-/*
- * TX data handlers.
+/**
+ * rt2x00pci_write_tx_data - Initialize data for TX operation
+ * @entry: The entry where the frame is located
+ *
+ * This function will initialize the DMA and skb descriptor
+ * to prepare the entry for the actual TX operation.
  */
-int rt2x00pci_write_tx_data(struct rt2x00_dev *rt2x00dev,
-			    struct data_queue *queue, struct sk_buff *skb);
+int rt2x00pci_write_tx_data(struct queue_entry *entry);
 
 /**
  * struct queue_entry_priv_pci: Per entry PCI specific information