Frameworks/base: Wall Werror in libs/hwui

Turn on -Wall -Werror in libs/hwui. Fix errors.

Change-Id: I74962d08c889712dacbd0d86d6760fc10802b6bd
diff --git a/libs/hwui/AmbientShadow.cpp b/libs/hwui/AmbientShadow.cpp
index cb3a002..2d1cf78 100644
--- a/libs/hwui/AmbientShadow.cpp
+++ b/libs/hwui/AmbientShadow.cpp
@@ -121,7 +121,7 @@
     *totalUmbraCount = 0;
     if (!isCasterOpaque) {
         // Add the centroid if occluder is translucent.
-        *totalVertexCount++;
+        (*totalVertexCount)++;
         *totalIndexCount += 2 * innerVertexCount + 1;
         *totalUmbraCount = innerVertexCount;
     }