XFA: Remove relative includes outside of xfa/.

R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1572523002 .
diff --git a/fpdfsdk/include/javascript/IJavaScript.h b/fpdfsdk/include/javascript/IJavaScript.h
index 0ce866c..6b15467 100644
--- a/fpdfsdk/include/javascript/IJavaScript.h
+++ b/fpdfsdk/include/javascript/IJavaScript.h
@@ -11,7 +11,7 @@
 #include "core/include/fxcrt/fx_system.h"
 
 #ifdef PDF_ENABLE_XFA
-#include "../../../xfa/include/fxjse/fxjse.h"
+#include "xfa/include/fxjse/fxjse.h"
 #endif  // PDF_ENABLE_XFA
 
 class CPDFDoc_Environment;