D28981: fix clang warning

[Smit Patil]

smitpatil added a reviewer: KWin.

REPOSITORY
  R108 KWin

REVISION DETAIL
  https://phabricator.kde.org/D28981

To: smitpatil, #kwin
Cc: kwin, smitpatil, Orage, cacarry, LeGast00n, The-Feren-OS-Dev, cblack, jraleigh, zachus, fbampaloukas, mkulinski, ragreen, jackyalcine, iodelay, crozbo, bwowk, ZrenBot, ngraham, alexeymin, himcesjf, lesliezhai, ali-mohamed, hardening, romangg, jensreuterberg, abetts, sebas, apol, ahiemstra, mart
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.kde.org/pipermail/kwin/attachments/20200419/4c7f2a72/attachment.html>