kconfig/nconf: Initialize the default locale at startup

Fix bug where make nconfig doesn't initialize the default locale, which
causes ncurses menu borders to be displayed incorrectly (lqqqqk) in
UTF-8 terminals that don't support VT100 ACS by default, such as PuTTY.

Signed-off-by: Jakub Horký <jakub.git@horky.net>
Link: https://patch.msgid.link/20251014144405.3975275-2-jakub.git@horky.net
[nathan: Alphabetize locale.h include]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Author: Jakub Horký

scripts/kconfig/nconf.c

@@ -7,6 +7,7 @@
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
 #endif
+#include <locale.h>
 #include <string.h>
 #include <strings.h>
 #include <stdlib.h>
@@ -1478,6 +1479,8 @@ int main(int ac, char **av)
 	int lines, columns;
 	char *mode;
 
+	setlocale(LC_ALL, "");
+
 	if (ac > 1 && strcmp(av[1], "-s") == 0) {
 		/* Silence conf_read() until the real callback is set up */
 		conf_set_message_callback(NULL);