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

# gpg: Signature made Wed Jun 24 16:37:23 2015 BST using RSA key ID 81AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>"
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>"

* remotes/stefanha/tags/net-pull-request:
  net: simplify net_client_init1()
  net: drop if expression that is always true
  net: raise an error if -net type is invalid
  net: replace net_client_init1() netdev whitelist with blacklist
  net: add missing "netmap" to host_net_devices[]

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