MFC 258869:
Fix an off-by-one error in r228960.  The maximum priority delta provided
by SCHED_PRI_TICKS should be SCHED_PRI_RANGE - 1 so that the resulting
priority value (before nice adjustment) is between SCHED_PRI_MIN and
SCHED_PRI_MAX, inclusive.
MFC r259520:
  Fix copy/paste typo.
MFC r259724:

Apply upstream commit 33312fd828e59c78ae4ee30fd70d0ca109748cf0 (by
zoulasc) to contrib/file:

  don't write a char to a pointer.
MFC 259014: There is no sysctl with the MIB { CTL_KERN, KERN_MAXID }.