for-linus-3.12-merge minor 9p fixes and tweaks for 3.12 merge window

The first fixes namespace issues which causes a kernel
NULL pointer dereference, the second fixes uevent
handling to work better with udev, and the third
switches some code to use srlcpy instead of strncpy
in order to be safer.

All changes have been baking in for-next for at least
2 weeks.
This tag has no release notes.