UPSTREAM: console: SisUSB2VGA: Drop dummy con_font_get()

As done in commit:

  724ba8b30b04 ("console/dummy: leave .con_font_get set to NULL")

This drops the dummy .con_font_get(), as it could leave arguments
uninitialized.

Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Change-Id: I71d98ce1245f204c324c730a524c6e9a3ec26ef9
(cherry picked from commit ea92110bc048848967bd2a046675a006005c4f06)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>