Reset error status on the socket

Change-Id: Id9cb5c0ac3d51058b9c1481b30b8bbd53aedd4e9
Reviewed-on: http://review.couchbase.org/24419
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>