unpack-trees: rename "gently" flag to "quiet"

The gently flag was added in 17e4642 (Add flag to make unpack_trees()
not print errors. - 2008-02-07) to suppress error messages. The name
"gently" does not quite express that. Granted, being quiet is gentle but
it could mean not performing some other actions. Rename the flag to
"quiet" to be more on point.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/checkout.c

@@ -700,7 +700,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		topts.initial_checkout = is_cache_unborn();
 		topts.update = 1;
 		topts.merge = 1;
-		topts.gently = opts->merge && old_branch_info->commit;
+		topts.quiet = opts->merge && old_branch_info->commit;
 		topts.verbose_update = opts->show_progress;
 		topts.fn = twoway_merge;
 		if (opts->overwrite_ignore) {

unpack-trees.c

@@ -219,7 +219,7 @@ static int add_rejected_path(struct unpack_trees_options *o,
 			     enum unpack_trees_error_types e,
 			     const char *path)
 {
-	if (o->gently)
+	if (o->quiet)
 		return -1;
 
 	if (!o->show_all_errors)
@@ -1042,7 +1042,7 @@ static int unpack_nondirectories(int n, unsigned long mask,
 static int unpack_failed(struct unpack_trees_options *o, const char *message)
 {
 	discard_index(&o->result);
-	if (!o->gently && !o->exiting_early) {
+	if (!o->quiet && !o->exiting_early) {
 		if (message)
 			return error("%s", message);
 		return -1;
@@ -2343,7 +2343,7 @@ int bind_merge(const struct cache_entry * const *src,
 		return error("Cannot do a bind merge of %d trees",
 			     o->merge_size);
 	if (a && old)
-		return o->gently ? -1 :
+		return o->quiet ? -1 :
 			error(ERRORMSG(o, ERROR_BIND_OVERLAP),
 			      super_prefixed(a->name),
 			      super_prefixed(old->name));

unpack-trees.h

@@ -56,7 +56,7 @@ struct unpack_trees_options {
 		     diff_index_cached,
 		     debug_unpack,
 		     skip_sparse_checkout,
-		     gently,
+		     quiet,
 		     exiting_early,
 		     show_all_errors,
 		     dry_run;