Fix argument in alluxio-fuse unmount when argument has trailing slash
Fix argument in alluxio-fuse unmount when argument has trailing slash

Previously
integration/fuse/bin/alluxio-fuse unmount /path/to/mount/point
will work, but
integration/fuse/bin/alluxio-fuse unmount /path/to/mount/point/
will give error "/path/to/mount/point/ not mounted". Strip the trailing
slash so both would work.

Fixes #11203

pr-link: Alluxio/alluxio#14907
change-id: cid-774bf4facfe802a6a4433f25319f00a8d8d127bb
Alluxio/alluxio,wwjiang007/alluxio,Alluxio/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,Alluxio/alluxio,Alluxio/alluxio,Alluxio/alluxio,Alluxio/alluxio,Alluxio/alluxio,wwjiang007/alluxio,Alluxio/alluxio,wwjiang007/alluxio,Alluxio/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,wwjiang007/alluxio,Alluxio/alluxio,wwjiang007/alluxio