Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-3.0-pull-request...

Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-3.0-pull-request' into staging

Some fixes for linux-user:
- workaround for CMSG_NXTHDR bug
- two patches for ppc64/ppc64le host:
  fix fcntl() with *LK64 commands
  (seen when dpkg wants to lock the DB)
  fix reserved_va alignment (ppc64 needs
  a 64kB alignment)
- convert a forgotten fcntl() to safe_fcntl()

# gpg: Signature made Sun 15 Jul 2018 20:51:19 BST
# gpg:                using RSA key F30C38BD3F2FBE3C
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>"
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>"
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>"
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-3.0-pull-request:
  Zero out the host's `msg_control` buffer
  linux-user: fix mmap_find_vma_reserved()
  linux-user: convert remaining fcntl() to safe_fcntl()
  linux-user: ppc64: use the correct values for F_*LK64s

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