compat: fix 'GERAN Info' TLV return in 'NAS Get Cell Location Info'
The 'GERAN Info' TLV returned a "cell" GArray with array elements of the wrong format. This was fixed in the 'GERAN Info v2' update, but the compat method still needs to be able to return a GArray
We could return an empty GArray and be done with it, but providing a compat array with the old element type isn't a big deal either, so we try to do that.
This avoids breaking users that were correctly assuming the output GArray was always set if the TLV getter didn't fail.
Plus, other memleak fixes