tests/qemu-iotests: Explicit usage of Python 3 (scripts with __main__)

Use the program search path to find the Python 3 interpreter.

Patch created mechanically by running:

  $ sed -i "s,^#\!/usr/bin/\(env\ \)\?python$,#\!/usr/bin/env python3," \
       $(git grep -l 'if __name__.*__main__')

Reported-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200130163232.10446-4-philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

tests/qemu-iotests/030

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for image streaming.
 #

tests/qemu-iotests/040

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for image block commit.
 #

tests/qemu-iotests/041

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for image mirroring.
 #

tests/qemu-iotests/044

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests growing a large refcount table.
 #

tests/qemu-iotests/045

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for fdsets and getfd.
 #

tests/qemu-iotests/055

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for drive-backup and blockdev-backup
 #

tests/qemu-iotests/056

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for drive-backup
 #

tests/qemu-iotests/057

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for internal snapshot.
 #

tests/qemu-iotests/065

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test for additional information emitted by qemu-img info on qcow2
 # images

tests/qemu-iotests/093

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for IO throttling
 #

tests/qemu-iotests/096

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test that snapshots move the throttling configuration to the active
 # layer

tests/qemu-iotests/118

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test case for the QMP 'change' command and all other associated
 # commands

tests/qemu-iotests/124

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for incremental drive-backup
 #

tests/qemu-iotests/129

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests that "bdrv_drain_all" doesn't drain block jobs
 #

tests/qemu-iotests/132

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test mirror with unmap
 #

tests/qemu-iotests/136

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for block device statistics
 #

tests/qemu-iotests/139

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test cases for the QMP 'blockdev-del' command
 #

tests/qemu-iotests/147

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test case for NBD's blockdev-add interface
 #

tests/qemu-iotests/148

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Test the rate limit of QMP events
 #

tests/qemu-iotests/151

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
 # Tests for active mirroring
 #