Description of problem:
Workflows 'mkrescue' and 'savelayout' fail when the XFS mount point contains space.

Version-Release number of selected component (if applicable):
rear-2.4-12.el8.x86_64


How reproducible:
always

Steps to Reproduce:
[root@host1 ~]# lvcreate -l 256 -n lvol1 dg02
WARNING: xfs signature detected on /dev/dg02/lvol1 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/dg02/lvol1.
  Logical volume "lvol1" created.
[root@host1 ~]# mkfs.xfs /dev/dg02/lvol1
meta-data=/dev/dg02/lvol1        isize=512    agcount=4, agsize=65536 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=262144, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
Discarding blocks...Done.
[root@host1 ~]# mkdir /appl/foo\ bar
[root@host1 ~]# mount /dev/dg02/lvol1 /appl/foo\ bar/
[root@host1 ~]# rear savelayout
ERROR: Failed to save XFS options of /dev/mapper/dg02-lvol1
Aborting due to an error, check /var/log/rear/rear-host1.log for details
Terminated


Actual results:
rear savelayout fails

Expected results:
rear savelayout succeeds


Additional info:
excerpt from the log file:

Relax-and-Recover 2.4 / Git
Command line options: /usr/sbin/rear savelayout
...
Including layout/save/GNU/Linux/230_filesystem_layout.sh
Begin saving filesystem layout
Saving filesystem layout (using the findmnt command).
Processing filesystem 'xfs' on '/dev/mapper/dg02-lvol1' mounted at '/appl/foox20bar'
/appl/foox20bar: No such file or directory

fatal error -- couldn't initialize XFS library
ERROR: Failed to save XFS options of /dev/mapper/dg02-lvol1
==== Stack trace ====
Trace 0: /usr/sbin/rear:547 main
Trace 1: /usr/share/rear/lib/savelayout-workflow.sh:14 WORKFLOW_savelayout
Trace 2: /usr/share/rear/lib/framework-functions.sh:101 SourceStage
Trace 3: /usr/share/rear/lib/framework-functions.sh:49 Source
Trace 4: /usr/share/rear/layout/save/GNU/Linux/230_filesystem_layout.sh:224 source
Trace 5: /usr/share/rear/lib/_input-output-functions.sh:372 StopIfError
Message: Failed to save XFS options of /dev/mapper/dg02-lvol1
== End stack trace ==