kconfig/nconf: Initialize the default locale at startup

kconfig/nconf: Initialize the default locale at startup

[ Upstream commit 43c2931a95e6b295bfe9e3b90dbe0f7596933e91 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>