tty: serial: jsm: add space before the open parenthesis '('

This patch fixes the checkpatch.pl complains:

space required before the open parenthesis '('.

Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
Acked-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>