delete the duplicated variable definition

A duplicated variable definition is introduced by the early merge today
which should be fixed.

Change-Id: I1aef41d1002867988c05dbab2317365893f58569
Closes-Bug: #1237273
Merge "delete the duplicated variable definition"
Reduce the "minimal" set of required diagnostics

Change If631472081d16fe8c0b37575eb157a7b13d6fba4 introduced new restrictions
on the diagnostics API which are not valid with XenAPI and causes it to fail
tempest tests.

I haven't found documentation which describes the minimum set of diagnostics
so therefore I assume we can safely reduce this test to ensure a truly minimal
set

Closes bug: 1239209

Change-Id: I3e643d8e7a63b7dc42a912fab09ffc4222d463db