TestAcceptIgnoreSomeErrors was created to test that network
accept function ignores some errors. But conditions created
by the test also affects network reads. Change the test to
ignore these read errors when acceptable.

Fixes #10785

Change-Id: I3da85cb55bd3e78c1980ad949e53e82391f9b41e
Reviewed-on: https://go-review.googlesource.com/9942Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>