vc: move normal char processing from do_con_write

vc_con_write_normal now handles the complex normal characters
processing. It is no longer a part of do_con_write. So this patch makes
do_con_write pretty clean and obvious.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200615074910.19267-19-jslaby@suse.cz


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