Fix sorting issue when running restart.

[crweller]

After adding the pre-defined sorted list for SAP instance types I figured out that the restart doesn't take the right order.
In fact, the new varaible sorted_sap_facts, which contains the instance types, must be initialized every time the playbook is called.

After I figured this out the solution was quite simple, adding a task to initialise the variable as list;

My tests on a system with 2 instance types, which failed before, was successful.

Please review.

Some linting issues are solved too.

[marcelmamula]

@crweller This change is OK in terms of current state of this role.

Please keep in mind that this is now in conflict with approved #39 as you are touching same file and same linting issue fixes.