binder: Return EFAULT if we fail BINDER_ENABLE_ONEWAY_SPAM_DETECTION

All the other ioctl paths return EFAULT in case the
copy_from_user/copy_to_user call fails, make oneway spam detection
follow the same paradigm.

Fixes: a7dc1e6f ("binder: tell userspace to dump current backtrace when detected oneway spamming")
Acked-by: Todd Kjos <tkjos@google.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Luca Stefani <luca.stefani.ge1@gmail.com>
Link: https://lore.kernel.org/r/20210506193726.45118-1-luca.stefani.ge1@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>