realloc maybe too big (t2.c)

Originally reported on Google Code with ID 26

```
Hello,

t2.c
line 568 :

cblk->data = (unsigned char*) opj_realloc(cblk->data, (cblk->len + seg-
>newlen) * sizeof(unsigned char*)); // <-- I believe this was meant to be 
sizeof(unsigned char)


```

Reported by `anton.lionel` on 2010-05-05 14:28:19
