This patch updates the vmmouse handler registration and activation.
Old behavior:
vmmouse_read_id, vmmouse_request_relative and vmmouse_request_absolute
unregister the handler and re-register it.
New behavior:
vmmouse_request_relative and vmmouse_request_absolute will unregister
the handler in case the mode did change. Then register and active the
handler with current mode if needed.
Note that the old code never ever *activates* the handler, so the
vmmouse doesn't receive events. This trips up Fedora 14 for example:
Boot a default install without usb tablet, watch the X-Server activating
the vmmouse then, enjoy a non-functional mouse.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>