[PATCH] ieee1394: skip dummy loop in build_speed_map

The last loop in ieee1394 core's speed calculation is not required
unless ieee1394.h::IEEE1394_SPEED_MAX is changed from its current value
of 3.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>