scripts/lnr: update for python3

Change shebang line to python3 and add parentheses to print

(From OE-Core rev: 85b6a53386382c0d92b5bea545c2db5e0204e629)

Signed-off-by: Allen Wild <allenwild93@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lnr

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#! /usr/bin/env python3
 
 # Create a *relative* symlink, just like ln --relative does but without needing
 # coreutils 8.16.
@@ -6,7 +6,7 @@
 import sys, os
 
 if len(sys.argv) != 3:
-   print "$ lnr TARGET LINK_NAME"
+   print("$ lnr TARGET LINK_NAME")
    sys.exit(1)
 
 target = sys.argv[1]