hwc: Use proper typecasts

- Remove compiler warnings
- Use proper typecasts

Change-Id: I7391f32ae31283239f5cebb93b02f3ce3a5c99f3
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index ad023ad..ed68988 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -189,7 +189,7 @@
 }
 
 inline hwc_rect_t integerizeSourceCrop(const hwc_frect_t& cropF) {
-    hwc_rect_t cropI = {0};
+    hwc_rect_t cropI = {0,0,0,0};
     cropI.left = int(ceilf(cropF.left));
     cropI.top = int(ceilf(cropF.top));
     cropI.right = int(floorf(cropF.right));