Merge branch 'hpfs-patches' (patches from Mikulas Patocka)

Merge branch 'hpfs-patches' (patches from Mikulas Patocka)

Merge hpfs updates from Mikulas Patocka.

Mainly fstrim support, with some minor other cleanups.

These were actually sent during the merge window, but I wanted to wait
for the FSTRIM compat handling cleanup before applying them.  Mikulas
sent that earlier today.

* emailed patches from Mikulas Patocka <mikulas@twibright.com>:
  hpfs: hpfs_error: Remove static buffer, use vsprintf extension %pV instead
  hpfs: kstrdup() out of memory handling
  hpfs: Remove unessary cast
  hpfs: add fstrim support