Fix Share Migration tempest tests

This patch addresses issues commented on
change I64b0a3ee77b27278cc294f72702408a27888e0e9
after it was merged, according to bug below.

Closes-bug: #1494000
Change-Id: I9079ea16e0edc359b380705bebba2a7e98446d5c
4 files changed
tree: 475d10973f4796fabea223c8258a59fafc002571
  1. manila_tempest_tests/