gcc 4.3 correctly determines that input() is unused and gives the
following warning:

<--  snip  -->

...
  HOSTCC  scripts/kconfig/zconf.tab.o
scripts/kconfig/lex.zconf.c:1628: warning: ‘input’ defined but not used
...

<--  snip  -->

Fix it by adding %option noinput to scripts/kconfig/zconf.l and
regeneration of scripts/kconfig/lex.zconf.c_shipped.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>