kconfig: simplify symbol-search code

There is no need for a double indirection in the temporary array that
stores the internediate search results.

Reported-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Jean Delvare <jdelvare@suse.de>