staging/lustre/llite: don't panic when fid is insane

LASSERT should never be done on data that is
received to over the network. Return EINVAL
when server returns invalid fid despite of
it_status == 0.

Signed-off-by: Sergey Cheremencev <sergey.cheremencev@seagate.com>
Seagate-bug-id: MRP-3073
Reviewed-on: http://review.whamcloud.com/17985
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7422


Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>