Merge branch 'ti/glibc-stdio-mutex-from-signal-handler' into maint

Merge branch 'ti/glibc-stdio-mutex-from-signal-handler' into maint

Allocation related functions and stdio are unsafe things to call
inside a signal handler, and indeed killing the pager can cause
glibc to deadlock waiting on allocation mutex as our signal handler
tries to free() some data structures in wait_for_pager().  Reduce
these unsafe calls.

* ti/glibc-stdio-mutex-from-signal-handler:
  pager: don't use unsafe functions in signal handlers