LU-8962 lfs: Handle non-lustre and multiple args

LU-8962 lfs: Handle non-lustre and multiple args

This patch addresses:

01: Handle multiple filesystems provided to 'lfs df'
02: Correctly report 'EOPNOTSUPP' for filesystems which
    are non-Lustre.
03: Make changes to test-framework.sh to handle modified
    return value from 'lfs df'. This changes For compatibility
    reason, ignores and masquerades EOPNOTSUPP as success.

The final return value is 0 for _all_ success or
value of the first failure for even a single failure
seen during the argument processing

sanity/56e Test-case added.

Lustre-change: https://review.whamcloud.com/42126
Lustre-commit: 2d714041ba718853be700960b76769a8fb44cf51

LU-15465 tests: conf-sanity failed with code 95

conf-sanity tests 27b, 47 and 84 (the tests execute 'fail mds1' and
then 'cleanup' at the end of test) failed with code EOPNOTSUPP because
of 'set -e' and lfs df <non_lustre> return code 95.
The scenario:
test_27b () {
  facet_failover $SINGLEMDS
    change_active mds1
  ...
  cleanup -> umount_client $MOUNT
}
formatall
  stopall
    activemds=`facet_active mds1`
    if [ $activemds != "mds1" ]; then
       fail mds1
         clients_up
           lfs_df_check
             + local clients=fre0111,fre0112
             + local rc
             + [ -z fre0111,fre0112 ]
             + pdsh -S -w fre0111,fre0112
                 /usr/bin/lfs df /mnt/lustre << lustre not mounted
pdsh@fre0111: fre0111: ssh exited with exit code 95
pdsh@fre0111: fre0112: ssh exited with exit code 95

To reproduce the issue just run:
  ONLY="27b" sh conf-sanity.sh or:
  ONLY="47" sh conf-sanity.sh or:
  ONLY="84" sh conf-sanity.sh

Lustre-change: https://review.whamcloud.com/46236
Lustre-commit: 242fc2ccbacaf171159a20d59c9633707d8fbf66

Fixes: 2d714041ba ("LU-8962 lfs: Handle non-lustre and multiple args")
Signed-off-by: Elena Gryaznova <elena.gryaznova@hpe.com>
HPE-bug-id: LUS-10680

Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I73287d21792d89b8cde672acdaf9c9caf829522f
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51690
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>