Fix bug in 2703 (commadpt) devices

While waiting for a bind() to succeed, attempting
a devinit or detach or anything that results in a
command getting sent to the device thread can
result in the command getting ignored or the
device getting hung due to a read from the wrong
end of the command pipe.  Also, the wfd file
descriptor set is specified twice in a call to
select().  The second one should be xfd.  Both
issues are addressed by this fix.

commadpt.c

@@ -1242,12 +1242,12 @@ static void *commadpt_thread(void *vca)
                     FD_ZERO(&rfd);
                     FD_ZERO(&wfd);
                     FD_ZERO(&xfd);
-                    FD_SET(ca->pipe[1],&rfd);
+                    FD_SET(ca->pipe[0],&rfd);
                     tv.tv_sec=5;
                     tv.tv_usec=0;
 
                     release_lock(&ca->lock);
-                    rc=select(ca->pipe[1]+1,&rfd,&wfd,&wfd,&tv);
+                    rc=select(ca->pipe[0]+1,&rfd,&wfd,&xfd,&tv);
                     obtain_lock(&ca->lock);
                     /*
                      * Check for a shutdown condition again after the sleep
@@ -1262,7 +1262,7 @@ static void *commadpt_thread(void *vca)
                     if(rc!=0)
                     {
                         /* Ignore any other command at this stage */
-                        read_pipe(ca->pipe[1],&b,1);
+                        read_pipe(ca->pipe[0],&b,1);
                         ca->curpending=COMMADPT_PEND_IDLE;
                         signal_condition(&ca->ipc);
                     }