USB: legotower: remove unneeded tracing macros

Remove the unneeded tracing macros in this driver.  The kernel has a
built-in trace function that can be used if this is really still needed.

Cc: Juergen Stuber <starblue@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>