script: fix generate assets (pingcap#1107)

Author: baurine

scripts/embed_ui_assets.sh

@@ -32,7 +32,7 @@ fi
 echo "+ Embed UI assets"
 
 cd "$PROJECT_DIR/scripts"
-go run generate_assets.go "$PROJECT_DIR/ui/build" $BUILD_TAG_PARAMETER
+go run generate_assets.go "$PROJECT_DIR/ui/build" "$BUILD_TAG_PARAMETER"
 
 HANDLER_PATH=$PROJECT_DIR/pkg/uiserver/embedded_assets_handler.go
 mv assets_vfsdata.go $HANDLER_PATH

scripts/generate_assets.go

@@ -12,7 +12,7 @@ import (
 )
 
 func main() {
-	if len(os.Args) < 2 {
+	if len(os.Args) < 3 {
 		log.Fatal("Require 2 args")
 	}
 	directory := os.Args[1]