Whitelist OpenSSLs ERR_put_error() in leak-detective

As we do not invoke ERR_get/clear_error() in all error cases, the
error codes are not removed from the error queue. But it is save
to whitelist the put function, as it uses a circular buffer that
does not grow beyond ERR_NUM_ERRORS errors (16 by default).

src/libstrongswan/utils/leak_detective.c

@@ -207,6 +207,7 @@ char *whitelist[] = {
 	"ENGINE_load_builtin_engines",
 	"OPENSSL_config",
 	"ecdsa_check",
+	"ERR_put_error",
 	/* libgcrypt */
 	"gcry_control",
 	"gcry_check_version",