Remove unused map lookups

[fshahinfar1]

In the following program, the malloc statement will be replaced by the packet. The generated BPF code will first do a lookup to a map and then replace the pointer with the packet. It would be nice to track unused map lookups and remove them.

#include <arpa/inet.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include <sys/types.h>
#include <sys/socket.h>

#define BUFSIZE 128

int main(int argc, char *argv[])
{
    int fd;
    struct sockaddr_in sk_addr, addr;
    socklen_t addr_len;
    inet_pton(AF_INET, "127.0.0.1", &(sk_addr.sin_addr));
    sk_addr.sin_port = htons(8080);
    fd = socket(AF_INET, SOCK_DGRAM, 0);
    bind(fd, (struct sockaddr *)&sk_addr, sizeof(sk_addr));
    while (1) {
        char *buf = malloc(BUFSIZE);
        recvfrom(fd, buf, BUFSIZE, 0,
                (struct sockaddr *)&addr, &addr_len);
        /* Drop everything */
        free(buf);
    }
    return 0;
}

[fshahinfar1]

The issue should be solved (although the code might not be stable).