Merge remote-tracking branch 'remotes/marcandre/tags/chr-fix-pull-request' into staging

Merge remote-tracking branch 'remotes/marcandre/tags/chr-fix-pull-request' into staging

Chardev-related fixes

Hi

Here are some bug fixes worthy for 6.1.

thanks

# gpg: Signature made Thu 05 Aug 2021 13:52:03 BST
# gpg:                using RSA key 87A9BD933F87C606D276F62DDAE8E10975969CE5
# gpg:                issuer "marcandre.lureau@redhat.com"
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>" [full]
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>" [full]
# Primary key fingerprint: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/marcandre/tags/chr-fix-pull-request:
  chardev: report a simpler error about duplicated id
  chardev: give some context on chardev-add error
  chardev: fix qemu_chr_open_fd() with fd_in==fd_out
  chardev: fix qemu_chr_open_fd() being called with fd=-1
  chardev: fix fd_chr_add_watch() when in != out
  chardev: mark explicitly first argument as poisoned
  chardev/socket: print a more correct command-line address
  util: fix abstract socket path copy

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