Fix pre-ANSI C code in check-lxdialog.sh.

diff --git a/scripts/kconfig/lxdialog/check-lxdialog.sh b/scripts/kconfig/lxdialog/check-lxdialog.sh
index 9d2a4c58..364eaecb 100644
--- a/scripts/kconfig/lxdialog/check-lxdialog.sh
+++ b/scripts/kconfig/lxdialog/check-lxdialog.sh
@@ -43,7 +43,7 @@ trap "rm -f $tmp" 0 1 2 3 15
 check() {
         $cc -x c - -o $tmp 2>/dev/null <<'EOF'
 #include CURSES_LOC
-main() {}
+int main() { return 0; }
 EOF
 	if [ $? != 0 ]; then
 	    echo " *** Unable to find the ncurses libraries or the"       1>&2
