Fix potential memory leak on failure of ecx_gen_init()

Fix potential memory leak on failure of ecx_gen_init()

When ecx_gen_set_params() returns 0, it could have duplicated the memory
for the parameter OSSL_KDF_PARAM_PROPERTIES already in gctx->propq,
leading to a memory leak.

Reviewed-by: Paul Dale <ppzgs1@gmail.com>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26015)