No explicit target mount option - need to cd to target

[Volker Siegel]

fatrace shows events either for all filesystems, or for one filesystem only.

To specify the filesystem or mount point to work on, the option -c (--current-mount) is used.
But the option does not directly take an argument as mount point - it uses the
current directory as implicit mountpoint argument.
This is confusing, and creates the need for workarounds.

eg: "(cd /mnt/foo ; fatrace -c ) | ..." is used instead of "fatrace -c /mnt/foo | ..."

When using fatrace by calling exec(), the parent process would need to change it's current directory (?)
before exec() or use system() instead, using a shell to do the cd.