usb: gadget: f_fs: fix setup request handling

This patch fixes __ffs_ep0_queue_wait() function, which now returns number of
bytes transferred in USB request or error code in case of failure. This is
needed by ffs_ep0_read() function, when read data is copied to userspace.

It also cleans up code by removing usused variable ep0req_status.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_fs.c

@@ -228,7 +228,7 @@ static int __ffs_ep0_queue_wait(struct ffs_data *ffs, char *data, size_t len)
 	}
 
 	ffs->setup_state = FFS_NO_SETUP;
-	return ffs->ep0req_status;
+	return req->status ? req->status : req->actual;
 }
 
 static int __ffs_ep0_stall(struct ffs_data *ffs)

drivers/usb/gadget/u_fs.h

@@ -154,7 +154,6 @@ struct ffs_data {
 	 */
 	struct usb_request		*ep0req;		/* P: mutex */
 	struct completion		ep0req_completion;	/* P: mutex */
-	int				ep0req_status;		/* P: mutex */
 
 	/* reference counter */
 	atomic_t			ref;