Remove the call to `ls` that was used to determine the symlink
destination
Reasoning :
* `od` resolves symlink itself due to the use of `fopen`
* Prevent the behaviour of `od` which will hang if the filename is
empty (i.e. `/sbin/init` missing) as it will be waiting for `stdin`
compared to quitting with error if the file just doesn't exist
Fixes#3006