display: Remove klockwork warnings and errors.

Remove all klockwork warnings and errors for libgralloc,
libhwcomposer, liboverlay, libqdutils, libqservice, libvirtual,
libexternal libraries to avoid buffer overflow and memory leaks.

Change-Id: I078143bcbcf5e4b342156bd8305a644566f7cc4b
diff --git a/libhwcomposer/hwc_fbupdate.cpp b/libhwcomposer/hwc_fbupdate.cpp
index b81494d..78a05e9 100644
--- a/libhwcomposer/hwc_fbupdate.cpp
+++ b/libhwcomposer/hwc_fbupdate.cpp
@@ -45,7 +45,7 @@
 }
 
 IFBUpdate::IFBUpdate(hwc_context_t *ctx, const int& dpy) : mDpy(dpy) {
-    size_t size;
+    size_t size = 0;
     getBufferAttributes(ctx->dpyAttr[mDpy].xres,
             ctx->dpyAttr[mDpy].yres,
             HAL_PIXEL_FORMAT_RGBA_8888,