staging: skein: Removes skein_debug include

Removes skein_debug.h include since skein_debug.h is nonexistent.
Removes unneeded debug empty macro defines and their uses.

Signed-off-by: Eric Rost <eric.rost@mybabylon.net>
Reviewed-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>