ieee1394: nodemgr: fix startup of knodemgrd

Revert a thinko in commit d2f119fe:
When knodemgrd starts, it needs to sleep until host->generation was
incremented above its initial value of 0.  My wrong logic caused it to
start sending requests when the bus wasn't completely ready.  Seen as
"AT dma reset ctx=0, aborting transmission" messages in 2.6.19-rc1.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>