iiod: Support new protocol without ZSTD

If ZSTD was not enabled during compilation, the PRINT command will
simply send the uncompressed XML string. The client can then detect and
use the uncompressed string directly.

Signed-off-by: Paul Cercueil <[email protected]>

iiod/iiod.c

@@ -98,10 +98,11 @@ static void sig_handler_usr1(int sig)
 
 static void *get_xml_zstd_data(const struct iio_context *ctx, size_t *out_len)
 {
-#if WITH_ZSTD
 	const char *xml = iio_context_get_xml(ctx);
-	size_t len, xml_len = strlen(xml);
+	size_t xml_len = strlen(xml);
 	void *buf;
+#if WITH_ZSTD
+	size_t len;
 	size_t ret;
 
 	len = ZSTD_compressBound(xml_len);
@@ -118,11 +119,15 @@ static void *get_xml_zstd_data(const struct iio_context *ctx, size_t *out_len)
 	}
 
 	*out_len = ret;
-
-	return buf;
 #else
-	return NULL;
+	buf = iio_strdup(xml);
+	if (!buf)
+		return NULL;
+
+	*out_len = xml_len;
 #endif
+
+	return buf;
 }
 
 static void free_device_pdata(struct iio_context *ctx)