Make ENOBUFS a soft error

(cherry picked from commit ebf3083e)
13 jobs for 462-full-recv-queue-on-netbsd-v9_11 in 9 minutes and 52 seconds (queued for 8 seconds)
Status Job ID Name Coverage
  Precheck
passed precheck:debian:sid:amd64 #35625
amd64 docker linux

00:00:12

 
  Build
passed build:centos:centos6:amd64 #35626
amd64 docker linux

00:02:51

passed build:centos:centos7:amd64 #35627
amd64 docker linux

00:03:16

passed build:debian:sid:amd64 #35628
amd64 docker linux

00:04:25

passed build:debian:sid:i386 #35629
i386 docker linux

00:04:58

 
  Test
passed systemtest:centos:centos6:amd64 #35634
amd64 docker linux

00:04:28

passed systemtest:centos:centos7:amd64 #35635
amd64 docker linux

00:04:37

passed systemtest:debian:sid:amd64 #35636
amd64 docker linux

00:04:39

passed systemtest:debian:sid:i386 #35637
i386 docker linux

00:04:07

passed unittest:centos:centos6:amd64 #35630
amd64 docker linux

00:01:06

passed unittest:centos:centos7:amd64 #35631
amd64 docker linux

00:01:18

passed unittest:debian:sid:amd64 #35632
amd64 docker linux

00:01:13

passed unittest:debian:sid:i386 #35633
i386 docker linux

00:01:02