tests: migration/guestperf Python 2.6 argparse compatibility

Add the scripts/ directory to sys.path so Python 2.6 will be able to
import argparse.

Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Acked-by: NJohn Snow <jsnow@redhat.com>
Acked-by: NFam Zheng <famz@redhat.com>
Message-id: 20170825155732.15665-4-stefanha@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/migration/guestperf/shell.py

@@ -18,12 +18,14 @@
 #
 
 
-import argparse
-import fnmatch
 import os
 import os.path
-import platform
 import sys
+sys.path.append(os.path.join(os.path.dirname(__file__),
+                             '..', '..', '..', 'scripts'))
+import argparse
+import fnmatch
+import platform
 
 from guestperf.hardware import Hardware
 from guestperf.engine import Engine