This fixes a number of things that are warnings in the Mac compiler....

import/mac/collada_conditioner_mac.mm

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 81 matching lines @@
   [task setArguments:[NSArray arrayWithObjects:@"-E", in_filename_ns,
                                 @"-o", out_filename_ns, nil]];
 
   // We send the output to a pipe, even though the tool doesn't really
   // output anything.  This is so that the invocation of the command
   // will be synchronous, and we can be sure that the output file has
   // been written by the time we exit this function.
   NSPipe *pipe = [NSPipe pipe];
   [task setStandardOutput:pipe];
   [task launch];
-  NSData *data = [[pipe fileHandleForReading] readDataToEndOfFile];
+  [[pipe fileHandleForReading] readDataToEndOfFile];
   return true;
 }
 }  // end namespace o3d