remove gcc warnings

The following errors is output in my environment(Debian squeeze & GCC4.4.5).

```
src/recompress.c:73: warning: implicit declaration of function ‘strncpy’
src/recompress.c:73: warning: incompatible implicit declaration of built-in function ‘strncpy’
src/recompress.c:84: warning: incompatible implicit declaration of built-in function ‘strncpy’
src/recompress.c: In function ‘recompress_entry’:
src/recompress.c:108: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘size_t’
src/recompress.c:126: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘size_t’
src/recompress.c:126: warning: format ‘%d’ expects type ‘int’, but argument 3 has type ‘size_t’
```

This patch will remove them.