libgralloc: use proper types and type casts

- Use proper types for pointers
- Resolve compiler errors
- handle proper type casts
- remove unused variables

Change-Id: I628ebe174485d30abadea4ca40b67f9aab1a0652
diff --git a/libgralloc/gpu.h b/libgralloc/gpu.h
index 8712c6c..a34ff7e 100644
--- a/libgralloc/gpu.h
+++ b/libgralloc/gpu.h
@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2008 The Android Open Source Project
- * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,10 +51,10 @@
                              int format, int usage,
                              buffer_handle_t* pHandle,
                              int* pStride);
-    int gralloc_alloc_framebuffer_locked(size_t size, int usage,
+    int gralloc_alloc_framebuffer_locked(int usage,
                                          buffer_handle_t* pHandle);
 
-    int gralloc_alloc_framebuffer(size_t size, int usage,
+    int gralloc_alloc_framebuffer(int usage,
                                   buffer_handle_t* pHandle);
 
     static int gralloc_free(alloc_device_t* dev, buffer_handle_t handle);