Added fix to 'test_delete_saving_image' testcase

'test_delete_saving_image' fails because image
snapshot is produced quicker than tempest being able
to catch the 'SAVING' transition.

Hence, the testcase needs following refinement:-
1. testcase should catch the state of image in 'SAVING'
   state only and then delete the image.
   By this case, we can get the idea that image is
   deleted in 'SAVING' state only and the testcase will
   achieve its motto.
2. If the image trasits to a state other than
   'SAVING', testcase can just delete the image.

Related-Bug: #1713163
Signed-off by: Soniya Vyas<svyas@redhat.com>
Change-Id: I50606c67e9f626935878aaa61d0adbc236272054
1 file changed