TTY: serial/ifx6x60, initialize more

In ifx_spi_complete, 'more' is not initialized. It is set only if the
status is clear and only if the header is parsed OK. If any of those
is not true, 'more' can be used uninitialized in that function later.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>