nconf: add u, d command keys in scroll windows

They function just like they do in less(1).
Also correct some discrepancy between the help text and the code wrt
function keys.

Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/kconfig/nconf.c

@@ -83,10 +83,10 @@ static const char nconf_readme[] = N_(
 "Text Box    (Help Window)\n"
 "--------\n"
 "o  Use the cursor keys to scroll up/down/left/right.  The VI editor\n"
-"   keys h,j,k,l function here as do <SPACE BAR> for those\n"
-"   who are familiar with less and lynx.\n"
+"   keys h,j,k,l function here as do <u>, <d> and <SPACE BAR> for\n"
+"   those who are familiar with less and lynx.\n"
 "\n"
-"o  Press <Enter>, <F1>, <F5>, <F7> or <Esc> to exit.\n"
+"o  Press <Enter>, <F1>, <F5>, <F9>, <q> or <Esc> to exit.\n"
 "\n"
 "\n"
 "Alternate Configuration Files\n"

scripts/kconfig/nconf.gui.c

@@ -604,9 +604,11 @@ void show_scroll_win(WINDOW *main_window,
 		switch (res) {
 		case KEY_NPAGE:
 		case ' ':
+		case 'd':
 			start_y += text_lines-2;
 			break;
 		case KEY_PPAGE:
+		case 'u':
 			start_y -= text_lines+2;
 			break;
 		case KEY_HOME:
@@ -632,10 +634,10 @@ void show_scroll_win(WINDOW *main_window,
 			start_x++;
 			break;
 		}
-		if (res == 10 || res == 27 || res == 'q'
-		    || res == KEY_F(F_BACK) || res == KEY_F(F_EXIT)) {
+		if (res == 10 || res == 27 || res == 'q' ||
+			res == KEY_F(F_HELP) || res == KEY_F(F_BACK) ||
+			res == KEY_F(F_EXIT))
 			break;
-		}
 		if (start_y < 0)
 			start_y = 0;
 		if (start_y >= total_lines-text_lines)