variadic function: fix syntax

Change-Id: If7cb720049169b99e6735a792534476281b26df1
diff --git a/twrpinstall/installcommand.cpp b/twrpinstall/installcommand.cpp
index 3b587b9..e4e5366 100755
--- a/twrpinstall/installcommand.cpp
+++ b/twrpinstall/installcommand.cpp
@@ -28,6 +28,7 @@
 #include <cutils/properties.h>
 
 #include "common.h"
+#include "twcommon.h"
 #include "installcommand.h"
 #include <ziparchive/zip_archive.h>
 #include "twinstall/install.h"