usb: gadget: f_accessory: Declare xfer as ssize_t at acc_read()

xfer should return ssize_t, not an unsigned value.

Fixes: d73e635 ("Merge 4.9.263 into android-4.9-q")
Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>
Change-Id: I1e527c042861abce324432ee3efd300297dee7dd
Signed-off-by: TogoFire <togofire@mailfence.com>

drivers/usb/gadget/function/f_accessory.c

@@ -661,9 +661,8 @@ static ssize_t acc_read(struct file *fp, char __user *buf,
 {
 	struct acc_dev *dev = fp->private_data;
 	struct usb_request *req;
-	ssize_t r = count;
+	ssize_t r = count, xfer;
 	ssize_t data_length;
-	unsigned xfer;
 	int ret = 0;
 
 	pr_debug("acc_read(%zu)\n", count);