USB: Serial: belkin_sa.c: remove debug module parameter

Now that all usb-serial modules are only using dev_dbg()
the debug module parameter does not do anything at all, so
remove it to reduce any confusion if someone were to try to
use it.

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

drivers/usb/serial/belkin_sa.c

@@ -37,8 +37,6 @@
 #include <linux/usb/serial.h>
 #include "belkin_sa.h"
 
-static bool debug;
-
 /*
  * Version Information
  */
@@ -514,6 +512,3 @@ MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_VERSION(DRIVER_VERSION);
 MODULE_LICENSE("GPL");
-
-module_param(debug, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(debug, "Debug enabled or not");