No real changes, just use KF_EXTENDED instead of hard-coded bit mask.

No real changes, just use KF_EXTENDED instead of hard-coded bit mask.

KF_EXTENDED is defined in Windows headers as the mask for extracting the
"extended" bit from LPARAM of the keyboard messages. Use it instead of
explicitly writing less clear "1 << 24".

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65520 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775