qa: move snap-hierarchy out of snaps workunits

The snapshot hierarchy it leaves behind can't be cleaned up by `rm -rf` which
breaks workunit cleanup. So, don't run this as part of normal snaps test.

Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>

qa/suites/fs/upgrade/snaps/tasks/1-client.yaml

@@ -9,5 +9,5 @@ tasks:
     cleanup: false
     clients:
       client.0:
-      - fs/snaps/snap-hierarchy.sh
+      - fs/snap-hierarchy.sh
 - print: "**** done snap hierarchy"

qa/suites/fs/upgrade/snaps/tasks/5-client-sanity.yaml

@@ -6,5 +6,5 @@ tasks:
       VERIFY: verify
     clients:
       client.0:
-      - fs/snaps/snap-hierarchy.sh
+      - fs/snap-hierarchy.sh
 - print: "**** done verify snap hierarchy"