Merge pull request #45036 from rishabh-d-dave/qa-fix-is_mounted

qa/cephfs: upgrade is_mounted() in mount.py

Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-by: Dhairya Parmar <dparmar@redhat.com>
Reviewed-by: Nikhilkumar Shelke <nshelke@redhat.com>
Reviewed-by: Ramana Raja <rraja@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Xiubo Li <xiubli@redhat.com>

diff --cc qa/tasks/cephfs/kernel_mount.py
Simple merge

diff --cc qa/tasks/cephfs/mount.py
Simple merge