EX-5360 lipe: lpcc handles unmounted lustre fs

EX-5360 lipe: lpcc handles unmounted lustre fs

If lustre fs is unmounted, lpcc daemon crashes while serving
'lpcc status' command. Fix it.

Signed-off-by: Lei Feng <flei@whamcloud.com>
Test-Parameters: trivial testlist=sanity-lipe
Change-Id: I5304745aed001fbe26b77ed3cebfaabfddfce11f
Reviewed-on: https://review.whamcloud.com/47572
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: John L. Hammond <jhammond@whamcloud.com>