of iod calling smb_iod_sendall()
g/c now unneeded request timeout expire check from smb_iod_sendall()
make it possible to override default request timeout - set timeout
value in smb_rq_init() to default value, caller can adjust the value
before calling smb_iod_sendrq(); value <=0 means no timeout
sent out, use mono_time instead microtime(), and simplify computation
in smb_iod_sendall(). Also count the timout once, not twice as previous code.
#if 0 iod->iod_lastrqsent, it was write-only
