Add support for storing compressed logs

If log_store_compressed is set, fio won't decompress for storing
them in a file. Instead, you can use --inflate-log=logfile.fz to
output the contents to stdout.

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/stat.c b/stat.c
index ccf08a6..979c810 100644
--- a/stat.c
+++ b/stat.c
@@ -1603,7 +1603,7 @@
 
 	s->val = val;
 	s->time = t;
-	s->ddir = ddir;
+	io_sample_set_ddir(iolog, s, ddir);
 	s->bs = bs;
 
 	if (iolog->log_offset) {