LU-5320: fixes for errors found by coccinelle

LU-5320: fixes for errors found by coccinelle

This patch fixes 3 errors found by coccinelle (a static analyser):

lustre/ptlrpc/nrs_tbf.c:312:2-8: preceding lock on line 307
lustre/fid/fid_handler.c:73:43-51: ERROR: cli is NULL but dereferenced.
lustre/lfsck/lfsck_lib.c:1564:1-10: second lock on line 1571

Signed-off-by: Frank Zago <fzago@cray.com>
Change-Id: Ic00a5c1dd331df879d6a10f11a07ef14f2beefd8
Reviewed-on: http://review.whamcloud.com/11047
Reviewed-by: Patrick Farrell <paf@cray.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Tested-by: Jenkins
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>