[PATCH] mxser_new: correct tty driver name

Mxser tty driver name should be ttyMI, not ttyM.  Correct this in mxser_new to
avoid conflicts with isicom driver, which is ttyM.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>