Упаковка двух символов в short int - C (СИ)

#include<stdio.h>
#include<stdlib.h>
 
void packCharacters(char, char);
void printBit(int);
 
main()
{
    char char1, char2;
 
    printf("Enter first character: ");
    scanf("%c", &char1);
    fflush(stdin);
    printf("Enter second character: ");
    scanf("%c", &char2);
 
    packCharacters(char1, char2);
 
    system("pause");
}
 
void packCharacters(char char1, char char2)
{
    unsigned short int result;
 
    result = char1;
    printBit(result);
    result <<= 8;
    printBit(result);
    result |= char2;
    
    printf("Result is %c\n", result);
    printf("Result in binary notation is\n");
    printBit(result);
    putchar('\n');
}
 
void printBit(int num)
{
    int i, mask = 1 << 15;
 
    for(i = 1; i <= 16; i++)
    {
        putchar(num & mask ? '1' : '0');
        num <<= 1;
 
        if(i % 4 == 0)
                putchar(' ');
    }
    putchar('\n');
}