Correctly print gpt UTF-16LE partition_name

[bamos]

Migrated from: https://github.com/wenluhu/gammaray-android/issues/18

Can likely be done with the iconv library. The following's resulting in a segfault, likely due to the cast from a *uint8_t[72] to char**.

struct gpt_partition_table_entry
{
    uint8_t partition_type_guid[16];
    uint8_t unique_partition_guid[16];
    uint64_t first_lba;
    uint64_t last_lba;
    uint64_t attribute_flags;
    uint8_t partition_name[72]; // 36 UTF-16LE code units.
}__attribute__((packed));

    iconv_t cd = iconv_open("US-ASCII", "UTF-16");
    size_t name_cstr_len = 36;
    char* partition_name_cstr = (char*) malloc(sizeof(char)*name_cstr_len);
    size_t name_utf16_len = name_cstr_len*2;
    int err = iconv(cd, (char**) &gpt_pe.partition_name, &name_utf16_len,
        &partition_name_cstr, &name_cstr_len);
    printf("err: %d\n", err);
    fprintf_green(stdout, "Partition Name: '%s'\n",
        partition_name_cstr);
    iconv_close(cd);