ide: fix LOCKDEP warning

commit 295f0004

 ("ide: don't execute
the next queued command from the hard-IRQ context") overlooked that
ide_do_drive_cmd() (used for REQUEST SENSE command handling) may still
invoke do_ide_request() (->request_fn) in the hard-IRQ context through
blk_start_queueing().  This resulted in a LOCKDEP warning after commit
b599bc7a1199419e122cb2e9ec6b0fa2cfbbc17b ("ide: use per-device request
queue locks (v2)").

Since calling blk_start_queuing() in ide_do_drive_cmd() doesn't make
much sense as the port is already marked as busy (so the execution of
the new command will be deferred anyway) then just remove it fixing
LOCKDEP warning and saving some CPU cycles at the same time.

Reported-and-tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Grissiom <chaos.proton@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>