FROMLIST: binder: remove unneeded cleanup code

(from https://patchwork.kernel.org/patch/9817817/

)

The buffer's transaction has already been freed before
binder_deferred_release. No need to do it again.

Change-Id: I412709c23879c5e45a6c7304a588bba0a5223fc3
Signed-off-by: Todd Kjos <tkjos@google.com>