scripts: change scripts to use system python instead of env

Just a small change to a couple of scripts to go from

#!/usr/bin/env python

to

#!/usr/bin/python

This shouldn't effect anyone, unless they don't install python there.

In preparation for python3, Fedora is doing a big push to change the scripts
to use the system python. This allows developers to put the python3 in
their path without fear of breaking existing scripts.

Now I am pretty sure anyone using python3 for testing purposes will probably
not run any of the scripts I changed, but Fedora has this automated tool
that checks for this stuff so I thought I would try to push it upstream.

Signed-off-by: Don Zickus <[e-mail]>
Acked-by: WANG Cong <[e-mail]>
Acked-by: Jarod Wilson <[e-mail]>
Signed-off-by: Michal Marek <[e-mail]>

arch/ia64/scripts/unwcheck.py

···
-#!/usr/bin/env python
+#!/usr/bin/python
 #
 # Usage: unwcheck.py FILE
 #

scripts/rt-tester/rt-tester.py

···
-#!/usr/bin/env python
+#!/usr/bin/python
 #
 # rt-mutex tester
 #

scripts/show_delta

···
-#!/usr/bin/env python
+#!/usr/bin/python
 #
 # show_deltas: Read list of printk messages instrumented with
 # time data, and format with time deltas.