kernel - Fix sendfile() based deadlock

* Fix a sendfile() based deadlock.  It turns out that after all of
  that work we can't soft-busy the page anyway because it can deadlock
  against a vfs_msync() -> ... -> vm_object_page_clean() sequence.

Reported-by: pavalos
kernel - Fix panic when usched is used to force a cpu w/the dfly scheduler (2)

* Missing file in last commit.