configutl.c: Resolve possible resource leak of config file

configutl.c: Resolve possible resource leak of config file

The coverity detects Resource leak here. It may come to leak when the
option is passed multiple times.

Resolve coverity scan issue 1646846

Signed-off-by: Norbert Pocs <norbertp@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
Reviewed-by: Neil Horman <nhorman@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/27623)