Protect strings on subshell/stat calls

[comio]

All scripts create subshells and compare the resulting output string with construct like this:

if [ $(stat ... "$P") != "btrfs" ]; then
...
fi

this construct doesn't protect from empty strings obtaining a syntax error.

To solve, we must use "eval" in order to solve escaping and protect the result:

if [ "$(eval stat ... \"$P\")" != "btrfs" ]; then
...
fi

[kdave]

I'd rather avoid using eval, in this case a temporary variable can do the job, like

fst=$(stat ...)
if [ "$fst" = "btrfs" ]; ...

[kdave]

Applied, thanks. I've squashed the 2 commits and updated the changelog.