resource leak in hmac_fromdns

*** CID 1440499:  Resource leaks  (RESOURCE_LEAK)
/lib/dns/hmac_link.c: 363 in hmac_fromdns()
357     	memset(hkey->key, 0, sizeof(hkey->key));
358     
359     	/* Hash the key if the key is longer then chosen MD block size */
360     	if (r.length > (unsigned int)isc_md_type_get_block_size(type)) {
361     		if (isc_md(type, r.base, r.length, hkey->key, &keylen)
362     		    != ISC_R_SUCCESS) {
   CID 1440499:  Resource leaks  (RESOURCE_LEAK)
   Variable "hkey" going out of scope leaks the storage it points to.
363     			return (DST_R_OPENSSLFAILURE);
364     		}
365     	} else {
366     		memmove(hkey->key, r.base, r.length);
367     		keylen = r.length;
368     	}