USB: Serial: ark3116.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: Rusty Russell <rusty@rustcorp.com.au>
CC: Alan Stern <stern@rowland.harvard.edu>
CC: Mauro Carvalho Chehab <mchehab@redhat.com>
CC: Bart Hartgers <bart.hartgers@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/ark3116.c

@@ -37,7 +37,6 @@
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
 
-static bool debug;
 /*
  * Version information
  */
@@ -749,9 +748,6 @@ MODULE_LICENSE("GPL");
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);
 
-module_param(debug, bool, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(debug, "Enable debug");
-
 /*
  * The following describes what I learned from studying the old
  * ark3116.c driver, disassembling the windows driver, and some lucky