Getting the same alert twice in a row is legal and normal,
especially on a fast device (like running in qemu).  Kind of
like interrupts.  So don't report duplicate alerts, and deliver
them normally.

[JD: Fixed subject]
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>