Error that i am getting: Error: insmod: error inserting './radaradc.ko': -1 Unknown symbol in module

radaradc.c:

#include <native/task.h>
#include <native/timer.h>

#include <linux/kernel.h>
#include <linux/module.h>

#include "../common.h"   //PORT definition

#define TASK_PRIO 99 	// Highest RT priority 
#define TASK_MODE 0 	// No flags
#define TASK_STKSZ 0 	// default Stack size 

#define MS 1000000	//1000000 ns = 1 ms

//In some systems, Timer Base or Task Period less than 10 micro seconds
//causes system to freeze
#define TIMER_BASE MS/100         //TIMER_BASE = 10 micro sec
#define TASK_BASE_PERIOD MS/1000  // 1 micro sec
#define TASK_DEFAULT_PERIOD 2500  // 2500 micro seconds

int sampleTime = TASK_DEFAULT_PERIOD;  //in micro sec. by default 2.5 ms.
MODULE_PARM(sampleTime, "i"); //read integer module parameter "sampleTime"

MODULE_LICENSE("GPL");

static RT_TASK td_adc;    //Real time task pointer

int TASK_PERIOD; //TASK_BASE_PERIOD * sampleTime (micro sec)

void adc (void *arg) {
   unsigned char pos=0, count=0, mov=1, fix=0x18, out;

   printk(KERN_ALERT "\nRadar adc running\n");
   rt_task_set_periodic(NULL, TM_NOW, 
               rt_timer_ns2ticks(TASK_PERIOD)); //set period
   for (;;) {
      rt_task_wait_period(); //deschedule until next period 
      
      //generate moving target position
      if (count==0) {
         if (pos<7) mov*=2;	  			 
         else       mov/=2;	   	  
         ++pos;
         if (pos>13) pos=0;
      }  
      
      //generate target signals
      if (count>169 && count<200) out=255; //fixed target in bottom 3 screen lines
      else switch(count) {	 //moving target around fixed target
         case 64 :
         case 74 :
         case 84 :
         case 104 :
         case 114 :	  	   	  		  	   
         case 124 : out=fix; break;			 
         case 94 : out=fix | mov; break;
         default : out=0;
      }

      //send signal to port
      outb (out, DATAPORT);       //outb takes aprox. 1 Micro sec.
      outb (count, COUNTPORT);    //outb takes aprox. 1 Micro sec.
      //printk(KERN_ALERT "%d ", count);  //check with dmesg
      ++count;
      if (count==200) count=0;
   } //for
}


int init_module(void) {

   //Set Task Period
   TASK_PERIOD=TASK_BASE_PERIOD*sampleTime;
   printk("\nRadar adc sucessfully loaded with\n");
   printk(KERN_ALERT "sampleTime = %d (micro secs)\n", sampleTime);
   
   rt_timer_start(TIMER_BASE); // Start timer base 
   rt_task_spawn(&td_adc, "adc", TASK_STKSZ, TASK_PRIO, TASK_MODE, 
                           &adc, NULL); //retorna 0 se OK ou <0 se erro
   
   return 0;
}

void cleanup_module(void)
{
	rt_task_delete(&td_adc);
        rt_timer_stop();
        printk("\nradar adc unloaded\n");
}

***************************************************************************
Makefile:
#Simple Xenomai module makefile
#had Nov 2006
#

obj-m   := radaradc.o

KDIR    := /lib/modules/$(shell uname -r)/build
PWD     := $(shell pwd)
EXTRA_CFLAGS := -I/usr/lib/xenomai/include -I/usr/include/


default:
        $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules

clean:
        $(MAKE) -C $(KDIR) SUBDIRS=$(PWD) clean