Our ABI for hostapd currently uses an old structure that only has one byte for the...

Our ABI for hostapd currently uses an old structure that only has one byte for the key index.  This means that the 'magic value' of -1 (255) for NONE is passed rather than the larger type we actually use internally.  To make comparisons work properly, I'm putting the magic value back at (uint8_t)-1 again so that a key index of 'none' with a MAC address that is passed into madwifi is interpreted correctly and the keys for that station are properly removed, rather than errors returned.

git-svn-id: http://madwifi-project.org/svn/madwifi/trunk@2798 0192ed92-7a03-0410-a25b-9323aeb14dbd