It causes recursive locking warning and is unneeded after
introduction of STARTED flag.

* Resume vs. stop is effectively solved by DISCONNECT flag.
* No problem in suspend vs. start -- urb is submitted even after open
  which is possible after connect which is called after start.
* Resume vs. start solved by STARTED flag.
* Suspend vs. stop -- no problem in killing urb and timer twice.
Reported-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>