There is a plan to build the kernel with -Wimplicit-fallthrough and
these places in the code produced warnings (W=1). Fix them up.

This commit remove the following warning:

  drivers/tty/vt/vt.c:2112:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
  drivers/tty/vt/vt.c:2237:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
Signed-off-by: NMathieu Malaterre <malat@debian.org>
Acked-by: NGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>