vnc: fix capslock tracking logic.

vnc: fix capslock tracking logic.

The capslock tracking logic added by commit
6b1325029d80455b9da7cd7bd84a88cb915b867c doesn't work correctly for vnc
clients without EXT_KEY_EVENT support.  The reason is that qemu converts
keysyms for letters to lowercase for the keysym2scancode lookup.  It
then also passes the lowercase value down to do_key_event(), but the
capslock tracking code needs it with the correct case to work properly.

This patch adds a new variable for the lowercase keysym so we'll keep
the unmodified value for do_key_event().

The keysym2scancode is not needed with EXT_KEY_EVENT capable clients
like any app based on the gtk-vnc widget, so I missed that case in
testing ...

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>