usb-storage: change remaining semaphore to completion

This patch (as1090) converts the one remaining semaphore in
usb-storage into a completion.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/storage/scsiglue.c

@@ -248,7 +248,7 @@ static int queuecommand(struct scsi_cmnd *srb,
 	/* enqueue the command and wake up the control thread */
 	srb->scsi_done = done;
 	us->srb = srb;
-	up(&(us->sema));
+	complete(&us->cmnd_ready);
 
 	return 0;
 }