MFC 259339

MFC 259339
      sbin/devd/devd.cc
          Increase the size of devd's client socket's send buffer from the
          default (8k) to 128k.  This prevents clients from getting
          POLLHUPped during event storms.  For example, during zpool creation,
          the kernel emits a resource.fs.zfs.statechange event for every vdev
          in the pool.  A 128k buffer is large enough to hold the statechange
          events for a pool with nearly 800 drives.

git-svn-id: svn://svn.freebsd.org/base/stable/9@260520 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f