sbsh(4) MPSAFE patch

[John Baldwin]

I have a patch to make sbsh(4) MPSAFE.  I have no hardware, however, so I 
can't test it.  This driver has the interesting "property" that it 
unconditionally sleeps waiting for an interrupt in several places like 
if_init and if_start that are very dubious.  It probably sleeps in interrupt 
thread context as a result.

http://www.FreeBSD.org/~jhb/patches/sbsh.patch

-- 
John Baldwin