madwifi patch cleanup and stability fixes

- fix a semi-random heisenbug by replacing the previous noderef fix with a simple hack that is not 100% correct, but safe.
- add ad-hoc atim fixes by bruno
- add napi polling fixes by sven-ola
- fix compile breakage with debug enabled

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@12838 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/madwifi/patches/406-monitor_r3711.patch

@@ -1,6 +1,6 @@
 --- a/ath/if_ath.c
 +++ b/ath/if_ath.c
-@@ -6371,7 +6371,7 @@
+@@ -6409,7 +6409,7 @@
  
  	/* Never copy the SKB, as it is ours on the RX side, and this is the 
  	 * last process on the TX side and we only modify our own headers. */
@@ -9,7 +9,7 @@
  	if (tskb == NULL) {
  		DPRINTF(sc, ATH_DEBUG_ANY,
  			"Dropping; ath_skb_removepad failed!\n");
-@@ -6379,6 +6379,8 @@
+@@ -6417,6 +6417,8 @@
  	}
  	
  	ieee80211_input_monitor(ic, tskb, bf, tx, tsf, sc);