Merge remote-tracking branch 'remotes/jasowang/tags/net-pull-request' into staging

# gpg: Signature made Fri 15 Jun 2018 03:47:09 BST
# gpg:                using RSA key EF04965B398D6211
# gpg: Good signature from "Jason Wang (Jason Wang on RedHat) <jasowang@redhat.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 215D 46F4 8246 689E C77F  3562 EF04 965B 398D 6211

* remotes/jasowang/tags/net-pull-request:
  vhost-user: delete net client if necessary
  e1000e: Do not auto-clear ICR bits which aren't set in EIAC
  net: Fix a potential segfault
  tap: set vhostfd passed from qemu cli to non-blocking

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>