tools: Fix bytes<->str mixing in python3
diff --git a/tools/btrfsdist.py b/tools/btrfsdist.py
index 72ea304..a9bf6e4 100755
--- a/tools/btrfsdist.py
+++ b/tools/btrfsdist.py
@@ -231,7 +231,7 @@
     if args.interval and (not args.notimestamp):
         print(strftime("%H:%M:%S:"))
 
-    dist.print_log2_hist(label, "operation")
+    dist.print_log2_hist(label, "operation", section_print_fn=bytes.decode)
     dist.clear()
 
     countdown -= 1