UPSTREAM: ANDROID: binder: prevent transactions into own process.

UPSTREAM: ANDROID: binder: prevent transactions into own process.

This can't happen with normal nodes (because you can't get a ref
to a node you own), but it could happen with the context manager;
to make the behavior consistent with regular nodes, reject
transactions into the context manager by the process owning it.

Reported-by: syzbot+09e05aba06723a94d43d@syzkaller.appspotmail.com
Signed-off-by: Martijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 7aa135fcf26377f92dc0680a57566b4c7f3e281b)
Change-Id: I3f6c0528fb2d3f8b835255b2a0ec603cab94626a