scripts/kconfig/nconf: dynamically alloc dialog_input_result

To support unlimited length string config items;

No check for realloc return value keeps code simple, and to be
consistent with other existing unchecked malloc in kconfig.

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index b113c50..73070cb 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -278,6 +278,9 @@
 /* the currently selected button */
 const char *current_instructions = menu_instructions;
 
+static char *dialog_input_result;
+static int dialog_input_result_len;
+
 static void conf(struct menu *menu);
 static void conf_choice(struct menu *menu);
 static void conf_string(struct menu *menu);
@@ -693,7 +696,6 @@
 {
 	struct symbol **sym_arr;
 	struct gstr res;
-	char dialog_input_result[100];
 	char *dialog_input;
 	int dres;
 again:
@@ -701,7 +703,7 @@
 			_("Search Configuration Parameter"),
 			_("Enter " CONFIG_ " (sub)string to search for "
 				"(with or without \"" CONFIG_ "\")"),
-			"", dialog_input_result, 99);
+			"", &dialog_input_result, &dialog_input_result_len);
 	switch (dres) {
 	case 0:
 		break;
@@ -1346,7 +1348,6 @@
 static void conf_string(struct menu *menu)
 {
 	const char *prompt = menu_get_prompt(menu);
-	char dialog_input_result[256];
 
 	while (1) {
 		int res;
@@ -1369,8 +1370,8 @@
 				prompt ? _(prompt) : _("Main Menu"),
 				heading,
 				sym_get_string_value(menu->sym),
-				dialog_input_result,
-				sizeof(dialog_input_result));
+				&dialog_input_result,
+				&dialog_input_result_len);
 		switch (res) {
 		case 0:
 			if (sym_set_string_value(menu->sym,
@@ -1390,14 +1391,13 @@
 
 static void conf_load(void)
 {
-	char dialog_input_result[256];
 	while (1) {
 		int res;
 		res = dialog_inputbox(main_window,
 				NULL, load_config_text,
 				filename,
-				dialog_input_result,
-				sizeof(dialog_input_result));
+				&dialog_input_result,
+				&dialog_input_result_len);
 		switch (res) {
 		case 0:
 			if (!dialog_input_result[0])
@@ -1422,14 +1422,13 @@
 
 static void conf_save(void)
 {
-	char dialog_input_result[256];
 	while (1) {
 		int res;
 		res = dialog_inputbox(main_window,
 				NULL, save_config_text,
 				filename,
-				dialog_input_result,
-				sizeof(dialog_input_result));
+				&dialog_input_result,
+				&dialog_input_result_len);
 		switch (res) {
 		case 0:
 			if (!dialog_input_result[0])