consoles: use if instead of switch-case in consw::con_cursor()

consoles: use if instead of switch-case in consw::con_cursor()

This is only a preparation for the following cleanup patch to make it
easier. Provided CM_ERASE is the only different, use 'if' instead of
'switch+case' in all those.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Tested-by: Helge Deller <deller@gmx.de> # parisc STI console
Link: https://lore.kernel.org/r/20240122110401.7289-28-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>