Initialize local variables to avoid data leak

The uninitialized local variables pick up
whatever the memory content was there on stack.
This data gets sent to the remote process in
case of a failed transaction, which is a security
issue. Fixed.

(Manual merge of master change
 12ba0f57d028a9c8f4eb3afddc326b70677d1e0c )

For b/23696300

Change-Id: I665212d10da56f0803b5bb772d14c77e632ba2ab
diff --git a/libs/gui/IGraphicBufferProducer.cpp b/libs/gui/IGraphicBufferProducer.cpp
index 1e28f9b..75c7cfc 100644
--- a/libs/gui/IGraphicBufferProducer.cpp
+++ b/libs/gui/IGraphicBufferProducer.cpp
@@ -304,7 +304,7 @@
             uint32_t h      = data.readInt32();
             uint32_t format = data.readInt32();
             uint32_t usage  = data.readInt32();
-            int buf;
+            int buf = 0;
             sp<Fence> fence;
             int result = dequeueBuffer(&buf, &fence, async, w, h, format, usage);
             reply->writeInt32(buf);
@@ -371,7 +371,7 @@
         } break;
         case QUERY: {
             CHECK_INTERFACE(IGraphicBufferProducer, data, reply);
-            int value;
+            int value = 0;
             int what = data.readInt32();
             int res = query(what, &value);
             reply->writeInt32(value);