madwifi: Fix building against linux 3.10

git-svn-id: svn://svn.openwrt.org/openwrt/packages@38372 3c298f89-4303-0410-b956-a3cf2f4a3e73
madwifi: Fix compile warnings

git-svn-id: svn://svn.openwrt.org/openwrt/packages@38373 3c298f89-4303-0410-b956-a3cf2f4a3e73