mkpidlock: close update loop in error path (JuliaLang#51902)

stdlib/FileWatching/src/pidfile.jl

@@ -77,6 +77,7 @@ mutable struct LockMonitor
  lock = new(at, fd, update)
  finalizer(close, lock)
  catch ex
+ update === nothing || close(update)
  tryrmopenfile(at)
  close(fd)
  rethrow(ex)
@@ -100,10 +101,13 @@ end
 function mkpidlock(at::String, proc::Process; kwopts...)
  lock = mkpidlock(at, getpid(proc); kwopts...)
  closer = @async begin
- wait(proc)
- close(lock)
+ try
+ wait(proc)
+ finally
+ close(lock)
+ end
  end
- isdefined(Base, :errormonitor) && Base.errormonitor(closer)
+ Base.errormonitor(closer)
  return lock
 end