scripts: Add Python 3 support to tracing/draw_functrace.py

Use the print function. This maintains Python 2 support and should have
no functional change.
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

scripts/tracing/draw_functrace.py

@@ -123,7 +123,7 @@ def main():
 		tree = tree.getParent(caller)
 		tree = tree.calls(callee, calltime)
 
-	print CallTree.ROOT
+	print(CallTree.ROOT)
 
 if __name__ == "__main__":
 	main()