USB: legotower: remove custom debug macro and module parameter

Now that we don't use the dbg() macro, remove it, and the module
parameter.  Also fix up the "dump_data" function to properly use the
dynamic debug core and the correct printk options, and don't call it
twice per function, as the data doesn't change from the beginning and
the end of the call.

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