remove non-germane comment

svn:r6640

src/common/util.c

@@ -198,10 +198,6 @@ _tor_memdup(const void *mem, size_t len DMALLOC_PARAMS)
   char *dup;
   tor_assert(mem);
   dup = _tor_malloc(len DMALLOC_FN_ARGS);
-  /* Performance note: Ordinarily we prefer strlcpy to strncpy.  But
-   * this function gets called a whole lot, and platform strncpy is
-   * much faster than strlcpy when strlen(s) is much longer than n.
-   */
   memcpy(dup, mem, len);
   return dup;
 }