scripts/kconfig/nconf: fix typo: unknow => unknown

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Acked-by: Arnaud Lacombe <lacombar@gmail.com>
diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index f8137b3..d3af04e 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/scripts/kconfig/nconf.gui.c
@@ -461,7 +461,7 @@
 				result[cursor_position] = res;
 				cursor_position++;
 			} else {
-				mvprintw(0, 0, "unknow key: %d\n", res);
+				mvprintw(0, 0, "unknown key: %d\n", res);
 			}
 			break;
 		}