Merge tag 'nbd-for-4.6' of git://git.pengutronix.de/git/mpa/linux-nbd into for-4.6/drivers

NBD for 4.6

Markus writes:

This pull request contains 7 patches for 4.6.

Patch 1 fixes some unnecessarily complicated code I introduced some versions
ago for debugfs.

Patch 2 removes the criticised signal usage within NBD to kill the NBD threads
after a timeout. This code was used for the last years and is now replaced by
simply killing the tcp connection.

Patches 3-6 are some smaller cleanups.

Patch 7 uevents for the userspace. This way udev/systemd can react on connected
NBD devices.