Merge remote-tracking branch 'aneesh/for-upstream' into staging

* aneesh/for-upstream:
  scripts/analyse-9p-simpletrace.py:	Add symbolic names for 9p operations.
  hw/9pfs: iattr_valid flags are kernel internal flags map them to 9p values.
  hw/9pfs: Use the correct signed type for different variables
  hw/9pfs: replace iovec manipulation with QEMUIOVector