Add job number specific dumping and fix atexit() error

The threads/process jobs should use _exit() so they don't run
the main atexit() function.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/filehash.h b/filehash.h
index a89a91f..993943a 100644
--- a/filehash.h
+++ b/filehash.h
@@ -4,6 +4,7 @@
 extern unsigned int file_hash_size;
 
 extern void file_hash_init(void *);
+extern void file_hash_exit(void);
 extern struct fio_file *lookup_file_hash(const char *);
 extern struct fio_file *add_file_hash(struct fio_file *);
 extern void remove_file_hash(struct fio_file *);