drive_mirror_stress: add error_context.context_aware to user error_context for log

Signed-off-by: NXiyue Wang <xiywang@redhat.com>

qemu/tests/drive_mirror_stress.py

@@ -10,6 +10,7 @@ from qemu.tests import drive_mirror
 
 class DriveMirrorStress(drive_mirror.DriveMirror):
 
+    @error_context.context_aware
     def load_stress(self):
         """
         load IO/CPU/Memory stress in guest;
@@ -26,6 +27,7 @@ class DriveMirrorStress(drive_mirror.DriveMirror):
         time.sleep(10)
         return None
 
+    @error_context.context_aware
     def unload_stress(self):
         """
         stop stress app
@@ -54,6 +56,7 @@ class DriveMirrorStress(drive_mirror.DriveMirror):
         session.close()
         return status == 0
 
+    @error_context.context_aware
     def verify_steady(self):
         """
         verify offset not decreased, after block mirror job in steady status;