When I used to write a lot of C code, my solution for this was to avoid calling memcmp() directly at all when I only cared about a yes/no on the match. Instead I used a wrapper I called memeq():

  int memeq( const void* lhs, const void* rhs, size_t count ) {
    return memcmp( lhs, rhs, count ) == 0;
  }

One could have an analogous memneq() with != 0, but I preferred to just use the ! operator on the memeq() result.

I would also use a typedef for the struct, so you don't have to keep writing "struct" everywhere:

  typedef struct {
    int x, y, z;
  } tmp;

With those two tricks, the erroneous memcmp() call becomes:

    if( ! memeq( m_result_original, m_result_my_version, sizeof(tmp) ) )

You're a lot less likely to get that wrong!