STM32F411E-DISCOVERY ADC function position problem

I'm using stm32f411e discovery board. I'm trying to use ADC1 Channel 3 (PA3) to read the potentiometer. When I put the function config for ADC is ADC_SingleChannel_Config() in #if (ADC_SINGLE_DEF), it is not working and the value return is out of 12 bit resolution. But when I put the ADC_SingleChannel_Config() after the Common_SetUp() in main() it works correctly. I dont know what is happening here. Please help me for this problem. Thanks very much!!!
Ps: All of functions is configurated and worked correctly. This is just my main.c file
My code

#include <stdio.h>
#include <stdint.h>
#include <string.h>

#include "stm32f4xx.h"
#include "stm32f4xx_it.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"

#include "main.h"
#include "macro.h"
#include "hw_cfg.h"
#include "systick_timer_cfg.h"
#include "usart_cfg.h"
#include "watchdog_cfg.h"
#include "rtc_config.h"
#include "adc_config.h"
#include "dma_config.h"

#include "xprintf.h"
#include "ring_buffer.h"

/* Marcro define common config ******************/
#define LED_DEF                 1
#define BUTTON_DEF              1
#define SYSTICK_DEF             1

#define IWDG_DEF                1
#define ADC_SINGLE_DEF          1


#define TIME_INTERVAL           1000 // ms

/* Global variables ******************************/
uint32_t now = 0;

/* Static prototype functions ***********************/
static void Common_SetUp(void);
static void Loop_Handler(void);


/**
 * *********************************************
 *               Main function
 */
int main(void) {
    Common_SetUp ();
//    ADC_SingleChannel_Config(); /* Put this function here is worked */
    /* Loop endless */
    while (1) {
        if (millis() - now > TIME_INTERVAL) {
            now = millis();
            /* TO DO */
            #if (ADC_SINGLE_DEF) /* Read potentiometer */
            uint16_t adc_ret = ADC_Read_SingleChannel (ADC1, ADC_Channel_3, 1);
            double potentiometer_val = (double)(adc_ret * 3) / 4095;
            PRINTLN("[PONTENTIONMETER READ]");
            PRINTLN("ADC = %1d", adc_ret);
            PRINTLN("VOL = %0.2f", potentiometer_val);
#endif
        }
    }
}


/**
 * *********************************************
 *          Common Set Up Peripherals
 */
void Common_SetUp() {
#if (LED_DEF)
    LEDs_Config();
    LEDs_Off (O_R_G_B);
#endif

#if (BUTTON_DEF)
    Button_Config();
#endif

#if (SYSTICK_DEF)
    SYSTICK_Config();
#endif

#if (IWDG_DEF)
    IWDG_Config();
#endif

#if (ADC_SINGLE_DEF)
    ADC_SingleChannel_Config(); /* Put this function here is not worked */
#endif
}

***My ADC_SingleChannel_Config()*** <br>

void ADC_SingleChannel_Config() {

GPIO_InitTypeDef GPIO_InitStructure;
ADC_InitTypeDef ADC_InitStructure;

/* Open Clock Gate *****/
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

/* IO Configuration ******/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStructure);

/* ADC Configuration ******/
ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;
ADC_InitStructure.ADC_ScanConvMode = DISABLE;
ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;
ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;
ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfConversion = 1;
ADC_Init(ADC1, &ADC_InitStructure);
/* Enable ADC */
ADC_Cmd(ADC1, ENABLE);

}