Merge remote-tracking branch 'sstabellini/tags/xen-20170516-tag' into staging

Xen 2017/05/16

# gpg: Signature made Tue 16 May 2017 08:18:32 PM BST
# gpg:                using RSA key 0x894F8F4870E1AE90
# gpg: Good signature from "Stefano Stabellini <stefano.stabellini@eu.citrix.com>"
# gpg:                 aka "Stefano Stabellini <sstabellini@kernel.org>"
# Primary key fingerprint: D04E 33AB A51F 67BA 07D3  0AEA 894F 8F48 70E1 AE90

* sstabellini/tags/xen-20170516-tag:
  xen: call qemu_set_cloexec instead of fcntl
  xen/9pfs: fix two resource leaks on error paths, discovered by Coverity
  configure: Remove -lxencall for Xen detection
  xen/mapcache: store dma information in revmapcache entries for debugging

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>