rust_binder: only print failure if error has source

rust_binder: only print failure if error has source

The commit that fixes BINDER_GET_EXTENDED_ERROR changed the condition
for printing transaction failures so errors are printed even if the
cause is a dead or frozen process. Undo this change so that the error
is only printed if the failure has an errno associated with it.

Cc: stable@kernel.org
Fixes: 77bfebf11077 ("rust_binder: fix BINDER_GET_EXTENDED_ERROR")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260708-get-extended-error-fix-printing-v1-1-6e293b213b70@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>