Merge remote-tracking branch 'remotes/mdroth/tags/qga-pull-2020-07-27-tag' into staging

qemu-ga patch queue for hard-freeze

* document use of -1 when pci_controller field can't be retrieved for
  guest-get-fsinfo
* fix incorrect filesystem type reporting on w32 for guest-get-fsinfo
  when a volume is not mounted

# gpg: Signature made Tue 28 Jul 2020 00:16:50 BST
# gpg:                using RSA key CEACC9E15534EBABB82D3FA03353C9CEF108B584
# gpg:                issuer "mdroth@linux.vnet.ibm.com"
# gpg: Good signature from "Michael Roth <flukshun@gmail.com>" [full]
# gpg:                 aka "Michael Roth <mdroth@utexas.edu>" [full]
# gpg:                 aka "Michael Roth <mdroth@linux.vnet.ibm.com>" [full]
# Primary key fingerprint: CEAC C9E1 5534 EBAB B82D  3FA0 3353 C9CE F108 B584

* remotes/mdroth/tags/qga-pull-2020-07-27-tag:
  qga/qapi-schema: Document -1 for invalid PCI address fields
  qga-win: fix "guest-get-fsinfo" wrong filesystem type

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