tty: vt: use switch+case in the ESnonstd case

To be uniform in the 'c' handling, use switch-case (with ranges) even in
the ESnonstd case in do_con_trol().

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20240202065608.14019-20-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>