If bailing out because there is nothing to receive in rp_do_receive(),
tty_ldisc_deref is not called.  Failure to do so increases the ref count
and causes release_dev() to hang since it can't get the ref count to 0.
Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
                ToRecv = space;
 
        if (ToRecv <= 0)
-               return;
+               goto done;
 
        /*
         * if status indicates there are errored characters in the
        }
        /*  Push the data up to the tty layer */
        ld->receive_buf(tty, tty->flip.char_buf, tty->flip.flag_buf, count);
+done:
        tty_ldisc_deref(ld);
 }