sbin/hammer - Remove trailing '/' from paths.
When operating PFSes through symbolic links, it was not
possible to specify the trailing backslash since that
translated to the PFS root dir instead of the symbolic link
to the PFS itself. This caused problems when upgrading or
downgrading PFSes (and probably in other cases too).
The error was "Directory not empty".
This commit should solve those cases, but keep in mind
there are other cases where it is actually not possible
to complete certain operations (like while destroying
PFSes).
Reported-by: Siju George, others