Bluetooth: SMP: Fail if remote and local public keys are identical

commit 6d19628f539fccf899298ff02ee4c73e4bf6df3f upstream.

This fails the pairing procedure when both remote and local non-debug
public keys are identical.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>