revisions API users: add straightforward release_revisions()

Add a release_revisions() to various users of "struct rev_list" in
those straightforward cases where we only need to add the
release_revisions() call to the end of a block, and don't need to
e.g. refactor anything to use a "goto cleanup" pattern.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sequencer.c

@@ -1347,6 +1347,7 @@ void print_commit_summary(struct repository *r,
 		log_tree_commit(&rev, commit);
 	}
 
+	release_revisions(&rev);
 	strbuf_release(&format);
 }
 
@@ -3415,6 +3416,7 @@ static int make_patch(struct repository *r,
 		unuse_commit_buffer(commit, commit_buffer);
 	}
 	strbuf_release(&buf);
+	release_revisions(&log_tree_opt);
 
 	return res;
 }
@@ -4525,6 +4527,7 @@ cleanup_head_ref:
 					      &log_tree_opt.diffopt);
 				log_tree_diff_flush(&log_tree_opt);
 			}
+			release_revisions(&log_tree_opt);
 		}
 		flush_rewritten_pending();
 		if (!stat(rebase_path_rewritten_list(), &st) &&