Fix bug #7733 - Invalid client DOS attributes on create can cause incorrect unix mode_t to be generated.
It turns out a client can send an NTCreateX call for a new file, but specify
FILE_ATTRIBUTE_DIRECTORY in the attribute list. Windows silently strips this,
but we don't - causing the unix_mode() function to go through the "mode bits
for new directory" codepath, instead of the "mode bits for new file" codepath.
Jeremy.
(cherry picked from commit
92adb686372a9b67e47efb5b051bc351212f1780)
(cherry picked from commit
6b4141e92151adaa0d2ef036657783a99ef517c6)