USB: OHCI: Fix race between ED unlink and URB submission

This patch fixes a bug introduced by commit 977dcfdc ("USB: OHCI:
don't lose track of EDs when a controller dies").  The commit changed
ed_state from ED_UNLINK to ED_IDLE too early, before finish_urb() had
been called.  The user-visible consequence is that the driver
occasionally crashes or locks up when an URB is submitted while
another URB for the same endpoint is being unlinked.

This patch moves the ED state change later, to the right place.  The
drawback is that now we may unnecessarily execute some instructions
multiple times when a controller dies.  Since controllers dying is an
exceptional occurrence, a little wasted time won't matter.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Heiko Przybyl <lil_tux@web.de>
Tested-by: Heiko Przybyl <lil_tux@web.de>
Fixes: 977dcfdc
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>