Python compat - print statement

Make sure all print statements are compatible with Python 2 and Python3 using
the `from __future__ import print_function` statement.

Differential Revision: https://reviews.llvm.org/D56249

llvm-svn: 350307
diff --git a/llvm/utils/extract_vplan.py b/llvm/utils/extract_vplan.py
index ac0055d..b4e34fc 100755
--- a/llvm/utils/extract_vplan.py
+++ b/llvm/utils/extract_vplan.py
@@ -4,6 +4,8 @@
 # and saves them in individual dot files (one for each plan). Optionally, and
 # providing 'dot' is installed, it can also render the dot into a PNG file.
 
+from __future__ import print_function
+
 import sys
 import re
 import argparse