mkimage: Add a few more messages for FIT failures

Add messages to make it clearer which part of the FIT creation is failing.
This can happen when an invalid 'algo' property is provided in the .its
file.

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/image-host.c

@@ -1292,8 +1292,12 @@ int fit_add_verification_data(const char *keydir, const char *keyfile,
 		ret = fit_image_add_verification_data(keydir, keyfile, keydest,
 				fit, noffset, comment, require_keys, engine_id,
 				cmdname, algo_name);
-		if (ret)
+		if (ret) {
+			printf("Can't add verification data for node '%s' (%s)\n",
+			       fdt_get_name(fit, noffset, NULL),
+			       fdt_strerror(ret));
 			return ret;
+		}
 	}
 
 	/* If there are no keys, we can't sign configurations */