Fix the use of pdfium

FPDF_LoadPage returns FPDF_PAGE and that's also what expected by other
APIs. There's no need for conversion.

This works now because FPDF_PAGE is defined as void*. But will fails
with new pdfium.

Bug: 155031873
Change-Id: I74381ec8ec36797a5901ea3de845c2b5d798ba0c
(cherry picked from commit 24fca180a1)

libs/hwui/jni/pdf/PdfEditor.cpp

@@ -110,7 +110,7 @@ static void nativeSetTransformAndClip(JNIEnv* env, jclass thiz, jlong documentPt
         jlong transformPtr, jint clipLeft, jint clipTop, jint clipRight, jint clipBottom) {
     FPDF_DOCUMENT document = reinterpret_cast<FPDF_DOCUMENT>(documentPtr);
 
-    FPDF_PAGE* page = (FPDF_PAGE*) FPDF_LoadPage(document, pageIndex);
+    FPDF_PAGE page = FPDF_LoadPage(document, pageIndex);
     if (!page) {
         jniThrowException(env, "java/lang/IllegalStateException",
                 "cannot open page");