Revert "cred: add missing return error code when set_cred_ucounts() failed"

This reverts commit 0855952e.

It breaks the abi and is not needed on Android kernels.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I65001e80f3776ae4ab56be5da555dba394278c68