2b1ebef8b8
Inside `getCurFilename`, there is this code snippit
```
if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
return 0;
```
If this is true, we return `"\0"`, but would leak the memory in
`FilenameBuf`.
This pull request adds a free before then to properly free the memory.
There was already a check that we allocated memory, so there is no need
to worry about freeing unallocated memory.