Use /usr/bin/env python2 instead of /usr/bin/python2

Signed-off-by: James Larrowe <larrowe.semaj11@gmail.com>

staging/newupdate.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python2
 
 import getopt, os, subprocess, sys
 

staging/patchgraph.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python2
 # -*- coding: utf-8 -*-
 #
 # Plot dependency graph for Staging patches.

staging/patchupdate.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python2
 # -*- coding: utf-8 -*-
 #
 # Automatic patch dependency checker and apply script generator.

staging/patchutils.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python2
 #
 # Python functions to read, split and apply patches.
 #

staging/progressbar.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python2
 #
 # Python progressbar functions.
 #