extattr_set_*() return type

Hmm, if these functions are expected to operate like 'write(2)' and are 
supposed to return the number of bytes written, shouldn't their return value 
be 'ssize_t' instead of 'int'?  It looks like the system calls themselves 
already do the right thing in setting td_retval[] (they assign a ssize_t to it 
and td_retval[0] can hold a ssize_t on all of our current platforms).  It 
would seem that the only change would be to the header and probably 
syscalls.master.  I guess this would require a symver bump to fix though.

-- 
John Baldwin