i386/i386/busdma_machdep.c 1.88 breaks isp

I have a qlogic 12160 based controller and the driver hangs at attach.
I have traced the problem to _bus_dmamap_load_buffer() looping
in the for (seg = *segp; buflen > 0 ; ) {...} loop forever. Backing
back down to i386/i386/busdma_machdep.c 1.87 fixes the problem.
I have not tracked it down to whether the fix to _bus_dmamap_load_buffer()
is bad or if isp has a bug that is exposed by this fix. At least I
can run now.


-Charles