kconfig: replace KERNELVERSION usage by the mainmenu's prompt

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Michal Marek <mmarek@suse.cz>
diff --git a/scripts/kconfig/nconf.c b/scripts/kconfig/nconf.c
index 801cc04..545e1af 100644
--- a/scripts/kconfig/nconf.c
+++ b/scripts/kconfig/nconf.c
@@ -633,13 +633,9 @@
 static const char *set_config_filename(const char *config_filename)
 {
 	int size;
-	struct symbol *sym;
 
-	sym = sym_lookup("KERNELVERSION", 0);
-	sym_calc_value(sym);
 	size = snprintf(menu_backtitle, sizeof(menu_backtitle),
-			_("%s - Linux Kernel v%s Configuration"),
-			config_filename, sym_get_string_value(sym));
+			"%s - %s", config_filename, rootmenu.prompt->text);
 	if (size >= sizeof(menu_backtitle))
 		menu_backtitle[sizeof(menu_backtitle)-1] = '\0';