kconfig: m/nconf: remove dead code to display value of bool choice

Previously, optional bool choices met the following conditions
simultaneously:

 - sym_is_choice(sym)
 - sym_is_changeable(sym)
 - type == S_BOOLEAN

It no longer occurs since 6a121588 ("kconfig: remove 'optional'
property support"). Remove the dead code.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/mconf.c

@@ -525,19 +525,12 @@ static void build_conf(struct menu *menu)
 
 		val = sym_get_tristate_value(sym);
 		if (sym_is_changeable(sym)) {
-			switch (type) {
-			case S_BOOLEAN:
-				item_make("[%c]", val == no ? ' ' : '*');
-				break;
-			case S_TRISTATE:
 			switch (val) {
 			case yes: ch = '*'; break;
 			case mod: ch = 'M'; break;
 			default:  ch = ' '; break;
 			}
 			item_make("<%c>", ch);
-				break;
-			}
 			item_set_tag('t');
 			item_set_data(menu);
 		} else {

scripts/kconfig/nconf.c

@@ -826,12 +826,6 @@ static void build_conf(struct menu *menu)
 
 		val = sym_get_tristate_value(sym);
 		if (sym_is_changeable(sym)) {
-			switch (type) {
-			case S_BOOLEAN:
-				item_make(menu, 't', "[%c]",
-						val == no ? ' ' : '*');
-				break;
-			case S_TRISTATE:
 			switch (val) {
 			case yes:
 				ch = '*';
@@ -844,8 +838,6 @@ static void build_conf(struct menu *menu)
 				break;
 			}
 			item_make(menu, 't', "<%c>", ch);
-				break;
-			}
 		} else {
 			item_make(menu, def_menu ? 't' : ':', "   ");
 		}