Revert "rtl8180: use NAPI for bottom-half processing"

This reverts commit 030725d2.

This commit relies on commit 5ed3bc72
("mac80211: use netif_receive_skb in ieee80211_tx_status callpath")
Unfortunately not all drivers are calling ieee80211_tx_status from a
compatible context, so that commit needs to be reverted in 2.6.36.

Signed-off-by: John W. Linville <linville@tuxdriver.com>