advice: remove read uses of most global `advice_` variables

In c4a09cc9ccb (Merge branch 'hw/advise-ng', 2020-03-25), a new API for
accessing advice variables was introduced and deprecated `advice_config`
in favor of a new array, `advice_setting`.

This patch ports all but two uses which read the status of the global
`advice_` variables over to the new `advice_enabled` API. We'll deal
with advice_add_embedded_repo and advice_graft_file_deprecated
separately.

Signed-off-by: Ben Boeckel <mathstuf@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/sequencer.c b/sequencer.c
index 7f07cd0..ab63eed 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -486,7 +486,7 @@ static int error_dirty_index(struct repository *repo, struct replay_opts *opts)
 	error(_("your local changes would be overwritten by %s."),
 		_(action_name(opts)));
 
-	if (advice_commit_before_merge)
+	if (advice_enabled(ADVICE_COMMIT_BEFORE_MERGE))
 		advise(_("commit your changes or stash them to proceed."));
 	return -1;
 }
@@ -1293,7 +1293,7 @@ void print_commit_summary(struct repository *r,
 	if (!committer_ident_sufficiently_given()) {
 		strbuf_addstr(&format, "\n Committer: ");
 		strbuf_addbuf_percentquote(&format, &committer_ident);
-		if (advice_implicit_identity) {
+		if (advice_enabled(ADVICE_IMPLICIT_IDENTITY)) {
 			strbuf_addch(&format, '\n');
 			strbuf_addstr(&format, implicit_ident_advice());
 		}
@@ -3041,7 +3041,7 @@ static int create_seq_dir(struct repository *r)
 	}
 	if (in_progress_error) {
 		error("%s", in_progress_error);
-		if (advice_sequencer_in_use)
+		if (advice_enabled(ADVICE_SEQUENCER_IN_USE))
 			advise(in_progress_advice,
 				advise_skip ? "--skip | " : "");
 		return -1;
@@ -3245,7 +3245,7 @@ int sequencer_skip(struct repository *r, struct replay_opts *opts)
 give_advice:
 	error(_("there is nothing to skip"));
 
-	if (advice_resolve_conflict) {
+	if (advice_enabled(ADVICE_RESOLVE_CONFLICT)) {
 		advise(_("have you committed already?\n"
 			 "try \"git %s --continue\""),
 			 action == REPLAY_REVERT ? "revert" : "cherry-pick");