LU-18067 utils: lfs getdirstripe hangs on FIFO

LU-18067 utils: lfs getdirstripe hangs on FIFO

The command "lfs getdirstripe -r ." hangs when
executed on a directory containing a FIFO file.

Steps to reproduce-

mkfifo testFile
lfs getdirstripe -r .
A test case, test_56ebb, has been added to sanity.sh
to verify this scenario.

Test-Parameters: trivial
HPE-bug-id: LUS-12266
Signed-off-by: Rajeev Mishra <rajeevm@hpe.com>
Change-Id: I62276e94383755a860b4195868dac554f90f7fe8
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55861
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Feng Lei <flei@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: Petros Koutoupis <petros.koutoupis@hpe.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>