drm/vmwgfx: Remove pointless code

There's no need to check for the presence of the hotplug
property just to return because this is the end of the function
so we're returning either way.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210209161700.335611-2-zackr@vmware.com