Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-5.1-pull-request' into staging

linux-user branch 20200714

Fix strace errno management
Fix Coverity erros in ioctl straces
Fix some netlinks errors
Fix semtimedop

# gpg: Signature made Tue 14 Jul 2020 08:31:56 BST
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-5.1-pull-request:
  linux-user: fix print_syscall_err() when syscall returned value is negative
  linux-user: fix the errno value in print_syscall_err()
  linux-user: add netlink RTM_SETLINK command
  linux-user: add new netlink types
  linux-user: Fix Coverity CID 1430271 / CID 1430272
  linux-user: refactor ipc syscall and support of semtimedop syscall
  linux-user: Use EPROTONOSUPPORT for unimplemented netlink protocols

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