[PATCH] serial: mpsc driver passes bad devname to request_irq()

The devname passed to request_irq() contained a '/' which is wrong.  At
a minimum, the '/' prevented the devname from showing up in
/proc/irq/<irq>/<devname>.  This patch replaces the '/' with a '-' to
fixes that problem.

Reported-by: Stephane Chazelas <Stephane@artesyncp.com>
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>