mm-video: venc: Fix reconbuffer free crash.

  - ION_IOC_FREE for reconbuffer is called with invalid fd -1.
    Modified code to check proper fd value before freeing.

Change-Id: I669d545bbdd9fe894a66c0e6f0279692c1460980

Author: c_sridur

mm-video/vidc/venc/src/video_encoder_device.cpp

@@ -1,5 +1,5 @@
 /*--------------------------------------------------------------------------
-Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
+Copyright (c) 2010-2013,2015 The Linux Foundation. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions are met:
@@ -1558,7 +1558,7 @@ OMX_U32 venc_dev::pmem_free()
   struct venc_recon_addr recon_addr;
   for (cnt = 0; cnt < recon_buffers_count; cnt++)
   {
-    if(recon_buff[cnt].pmem_fd)
+    if(recon_buff[cnt].pmem_fd > 0)
     {
       recon_addr.pbuffer = recon_buff[cnt].virtual_address;
       recon_addr.offset = recon_buff[cnt].offset;