common: fixed linker-list example

Last argument shouldn't be there.
Signed-off-by: NMateusz Zalega <m.zalega@samsung.com>
Acked-by: NMarek Vasut <marex@denx.de>
Cc: Tom Rini <trini@ti.com>

include/linker_lists.h

@@ -228,7 +228,7 @@
  * and it's name.
  *
  * Example:
- * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub, cmd.sub) = {
+ * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
  *         .x = 3,
  *         .y = 4,
  * };