D12165: Use QStorageInfo instead of a homegrown implementation

[Stefan Brüns]

bruns added a dependency: D11452: sanitizer: Improve device listing.

REPOSITORY
  R293 Baloo

REVISION DETAIL
  https://phabricator.kde.org/D12165

To: bruns, #baloo, michaelh
Cc: #frameworks, ashaposhnikov, michaelh, astippich, spoorun, ngraham, bruns, 
alexeymin