Fails in multistage build when re-linking libc.so.6 (file exists)

First stage
```
...
/lib64/libc.so.6 -> lib64/libc.so.6
...
```

later stage ...

```
...
snaggle link /usr/lib64/libc.so.6 lib64/libc.so.6: file exists
Usage:
snaggle FILE DESTINATION [flags]
Flags:
-h, --help help for snaggle
...
```
