LU-1589 lnet: read peers of /proc could be endless

LU-1589 lnet: read peers of /proc could be endless

There is a chance that reading /proc/sys/lnet/peers could be endless
because we didn't set correct condition for ending. This bug is
introduced by commit a07e9d350b3e500c7be877f6dcf54380b86a9cbe of LU-56

Signed-off-by: Liang Zhen <liang@whamcloud.com>
Change-Id: I25f6dad4a926bb7c62a4b1b1d4c3a86c783e3f7a
Reviewed-on: http://review.whamcloud.com/3251
Tested-by: Hudson
Reviewed-by: Doug Oucharek <doug@whamcloud.com>
Reviewed-by: Bobi Jam <bobijam@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>