test/py: Make print statements python 3.x safe

In python 3.x print must be called as a function rather than used as a
statement. Update uses of print to the function call syntax in order to
be python 3.x safe.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

test/py/test.py

@@ -7,6 +7,8 @@
 # Wrapper script to invoke pytest with the directory name that contains the
 # U-Boot tests.
 
+from __future__ import print_function
+
 import os
 import os.path
 import sys
@@ -26,7 +28,7 @@ except:
     traceback.print_exc()
     # Hint to the user that they likely simply haven't installed the required
     # dependencies.
-    print >>sys.stderr, '''
+    print('''
 exec(py.test) failed; perhaps you are missing some dependencies?
-See test/py/README.md for the list.'''
+See test/py/README.md for the list.''', file=sys.stderr)
     sys.exit(1)