[PATCH] Char: mxser_new, correct intr handler proto

Prototype of the driver's interrupt handler is old-fashioned, past changes
tell us, we won't get pt_regs as the 3rd argument.  There are only 2 params.

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