Fix uninitialised value

Fix uninitialised value

Do not read m_hoveredColumnHearderRoleIndex before it has been
initialised.

.6  0x00007fe00632182c in QList<KFileItemModel::RoleInfo>::Node::t
(this=<optimized out>, this=<optimized out>) at
/usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:153
.7  QList<KFileItemModel::RoleInfo>::at (i=3080252, this=0x7ffdf2e9bba8)
at /usr/include/x86_64-linux-gnu/qt5/QtCore/qlist.h:572
.8  DolphinView::eventFilter (this=0x5584bef25160,
watched=0x5584bef8a300, event=0x7ffdf2e9bd30) at
./src/views/dolphinview.cpp:978
.9  0x00007fe003ebbdda in
QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*,
QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
.10 0x00007fe004b6c782 in QApplicationPrivate::notify_helper(QObject*,
QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
.11 0x00007fe004b75411 in QApplication::notify(QObject*, QEvent*) ()
from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
.12 0x00007fe003ebc07a in QCoreApplication::notifyInternal2(QObject*,
QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
.13 0x00007fe004b72269 in QApplication::event(QEvent*) () from
/lib/x86_64-linux-gnu/libQt5Widgets.so.5
.14 0x00007fe004b6c793 in QApplicationPrivate::notify_helper(QObject*,
QEvent*) () from /lib/x86_64-linux-gnu/libQt5Widgets.so.5
.15 0x00007fe003ebc07a in QCoreApplication::notifyInternal2(QObject*,
QEvent*) () from /lib/x86_64-linux-gnu/libQt5Core.so.5
.16 0x00007fe003f14e0b in QTimerInfoList::activateTimers() () from
/lib/x86_64-linux-gnu/libQt5Core.so.5
.17 0x00007fe003f15754 in ?? () from
/lib/x86_64-linux-gnu/libQt5Core.so.5
.18 0x00007fe001d20d3b in g_main_context_dispatch () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
.19 0x00007fe001d756c8 in ?? () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
.20 0x00007fe001d1e3e3 in g_main_context_iteration () from
/lib/x86_64-linux-gnu/libglib-2.0.so.0
.21 0x00007fe003f15ad8 in
QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>)
() from /lib/x86_64-linux-gnu/libQt5Core.so.5
.22 0x00007fe003eba99b in
QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from
/lib/x86_64-linux-gnu/libQt5Core.so.5
.23 0x00007fe003ec2f34 in QCoreApplication::exec() () from
/lib/x86_64-linux-gnu/libQt5Core.so.5
.24 0x00005584bd2a9aad in main (argc=<optimized out>, argv=<optimized
out>) at ./src/main.cpp:249

BUG: 466110