USB: belkin_sa.c: remove dbg() tracing calls

dbg() was used a lot a long time ago to trace code flow.  Now that we have
ftrace, this isn't needed at all, so remove these calls.

CC: William Greathouse <wgreathouse@smva.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>