[PATCH] qconf: hide empty list items

This patch fixes showing empty config list items if "Option/Show All
Options" is turned on.  For example empty items appears on list of 'Block
Layer' menu.

Signed-off-by: Cyrill V. Gorcunov <gorcunov@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Oleg Verych <olecom@flower.upol.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>