common/iobuf.c: Remove dead code (opaque).

* common/iobuf.h (struct iobuf_struct): Remove field opaque.  Remove
all uses of it.

--
Signed-off-by: Neal H. Walfield <neal@g10code.com>.

common/iobuf.c

@@ -1,6 +1,7 @@
 /* iobuf.c  -  File Handling for OpenPGP.
  * Copyright (C) 1998, 1999, 2000, 2001, 2003, 2004, 2006, 2007, 2008,
  *               2009, 2010, 2011  Free Software Foundation, Inc.
+ * Copyright (C) 2015  g10 Code GmbH
  *
  * This file is part of GnuPG.
  *
@@ -1117,7 +1118,6 @@ iobuf_alloc (int use, size_t bufsize)
   a->d.size = bufsize;
   a->no = ++number;
   a->subno = 0;
-  a->opaque = NULL;
   a->real_fname = NULL;
   return a;
 }
@@ -1666,7 +1666,6 @@ iobuf_push_filter2 (iobuf_t a,
   a->nofast &= ~1;
   /* make a link from the new stream to the original stream */
   a->chain = b;
-  a->opaque = b->opaque;
 
   /* setup the function on the new stream */
   a->filter = f;

common/iobuf.h

@@ -97,9 +97,6 @@ struct iobuf_struct
                                    (passed to filter) */
   int no, subno;
   const char *desc;
-  void *opaque;			/* Can be used to hold any information
-                                   this value is copied to all
-                                   instances */
 };
 
 #ifndef EXTERN_UNLESS_MAIN_MODULE