patch-ids.h: add missing trailing parenthesis in documentation comment

Signed-off-by: Elijah Newren <newren@gmail.com>

Author: newren

patch-ids.h

@@ -37,7 +37,7 @@ int has_commit_patch_id(struct commit *commit, struct patch_ids *);
  *   struct patch_id *cur;
  *   for (cur = patch_id_iter_first(commit, ids);
  *        cur;
- *        cur = patch_id_iter_next(cur, ids) {
+ *        cur = patch_id_iter_next(cur, ids)) {
  *           ... look at cur->commit
  *   }
  */