Replace backticks with repr() or "%r"

From SF patch #852334.
diff --git a/Tools/scripts/suff.py b/Tools/scripts/suff.py
index ee7499f..dfb3da0 100755
--- a/Tools/scripts/suff.py
+++ b/Tools/scripts/suff.py
@@ -17,7 +17,7 @@
     keys = suffixes.keys()
     keys.sort()
     for suff in keys:
-        print `suff`, len(suffixes[suff])
+        print repr(suff), len(suffixes[suff])
 
 def getsuffix(filename):
     suff = ''