If ieee1394.h::IEEE1394_SPEED_MAX is bigger than the actual speed of an
1394b host adapter and the speed to another 1394b node was probed, a
bigger speed than actually used was kept in host->speed[n].  The only
resulting problem so far was sbp2 displaying bogus values in the syslog,
e.g. S3200 for actual S800 connections if IEEE1394_SPEED_MAX was S3200.
But other high-level drivers which access this field could get into more
trouble.  (Eth1394 is the only other in-tree driver which does so.  It
seems it is not affected.)

Nodemgr now clips this value according to the host adapter's link speed.

A pointer expression in nodemgr_check_speed is also changed for clarity.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>