Remove unnecessary mark as unused
`ret` is used always at line 1305 in statement:
`if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk, key, keylen ) ) == 0 )`
@@ -1261,7 +1261,6 @@ int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
return( ret );
#endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
#else
- ((void) ret);
((void) pwd);
((void) pwdlen);
#endif /* MBEDTLS_PEM_PARSE_C */
