sideband.c: replace int with size_t for clarity

sideband.c

@@ -69,7 +69,10 @@ void list_config_color_sideband_slots(struct string_list *list, const char *pref
  * of the line. This should be called for a single line only, which is
  * passed as the first N characters of the SRC array.
  *
- * NEEDSWORK: use "size_t n" instead for clarity.
+ * It is fine to use "int n" here instead of "size_t n" as all calls to this
+ * function pass an 'int' parameter. Additionally, the buffer involved in
+ * storing these 'int' values takes input from a packet via the pkt-line
+ * interface, which is capable of transferring only 64kB at a time.
  */
 static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
 {