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)

providers/implementations/keymgmt/ecx_kmgmt.c

@@ -510,7 +510,7 @@ static void *ecx_gen_init(void *provctx, int selection,
 #endif
     }
     if (!ecx_gen_set_params(gctx, params)) {
-        OPENSSL_free(gctx);
+        ecx_gen_cleanup(gctx);
         gctx = NULL;
     }
     return gctx;