do_epoll_ctl(): clean the failure exits up a bit

do_epoll_ctl(): clean the failure exits up a bit

commit 52c479697c9b73f628140dcdfcd39ea302d05482 upstream.

Mot-CRs-fixed: (CR)
CVE-Fixed: CVE-2020-0466
Bug: 147802478

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: I97468c95d3c22cc5f538dfcf78907aefa35a6503
Signed-off-by: Jignesh Patel <jignesh@motorola.com>
Reviewed-on: https://gerrit.mot.com/1796973
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
(cherry picked from commit 9210a4397626480be068aeb202b131c700f9804d)