LU-56 lnet: cleanup for LNet Event Queue

LU-56 lnet: cleanup for LNet Event Queue

This patch is just a cleanup patch for LNet Event Queue (EQ),
it's an intermediate patch for upcoming LNet SMP improvement
for EQ.

Signed-off-by: Liang Zhen <liang@whamcloud.com>
Change-Id: I2761c0c4118fa709a921b4060a7bd5ec6700a3f0
Reviewed-on: http://review.whamcloud.com/2924
Reviewed-by: Bobi Jam <bobijam@whamcloud.com>
Reviewed-by: Doug Oucharek <doug@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>