This involved reworking the usb_serial_debug_data() function too.
Based on a request from SuSE, and numerous user confusions with how
to enable this option.  Now that all usb-serial drivers are using
module_param() it can be set from the boot command line if the drivers
are built into the kernel.
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>