cluster: Update out of date comment
cluster: Update out of date comment

Commits e0fac16f8c1a3b06dd4e03ef6b4da630411bcd93 and
1001b1a2308139fbb7ae322f3bc3b627d3ddad85 reduced the number
of iterations in the runOnce() loop; this commit updates the
comment to be correct.

kelda/kelda,quilt/quilt,LuiseV/quilt,kelda/kelda,NetSys/quilt,ejj/quilt-dev,ejj/quilt-dev,NetSys/quilt,kelda/kelda,kklin/kelda,quilt/quilt,kayousterhout/quilt,quilt/quilt,LuiseV/quilt,kayousterhout/quilt,NetSys/quilt,kklin/quilt,kklin/quilt,LuiseV/quilt,ejj/quilt-dev,NetSys/quilt,LuiseV/quilt,kklin/kelda,kklin/quilt,LuiseV/quilt,quilt/quilt,ejj/quilt-dev,kelda/kelda,kklin/kelda,NetSys/quilt,kayousterhout/quilt,kklin/quilt,kayousterhout/quilt,kklin/kelda