rt2500pci: restoring missing line

In kernel version 2.6.26-rc9 my wireless LAN card worked; but in the
released 2.6.26, my RaLink rt2500 card wouldn't associate.

Git-bisect led me to this patch:

	61486e0f
	rt2x00: Remove ieee80211_tx_control argument from write_tx_desc()

I believe that there is a problem with that patch --- it
(inadvertantly) removes an extra line of code, that used to set the
DATABYTE_COUNT field.

This patch reinstates that line, and with it my card works again.
Signed-off-by: NPeter Chubb <peterc@gelato.unsw.edu.au>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2500pci.c

@@ -1220,6 +1220,7 @@ static void rt2500pci_write_tx_desc(struct rt2x00_dev *rt2x00dev,
 	rt2x00_set_field32(&word, TXD_W0_IFS, txdesc->ifs);
 	rt2x00_set_field32(&word, TXD_W0_RETRY_MODE,
 			   test_bit(ENTRY_TXD_RETRY_MODE, &txdesc->flags));
+	rt2x00_set_field32(&word, TXD_W0_DATABYTE_COUNT, skb->len);
 	rt2x00_set_field32(&word, TXD_W0_CIPHER_ALG, CIPHER_NONE);
 	rt2x00_desc_write(txd, 0, word);
 }