CDC-ACM: heed quirk also in error handling

If buffers are iterated over in the error case, the lower limits
for quirky devices must be heeded.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: Jean Rene Dawin <jdawin@math.uni-bielefeld.de>
Fixes: a4e7279c ("cdc-acm: introduce a cool down")
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200526124420.22160-1-oneukum@suse.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/class/cdc-acm.c

@@ -584,7 +584,7 @@ static void acm_softint(struct work_struct *work)
 	}
 
 	if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) {
-		for (i = 0; i < ACM_NR; i++) 
+		for (i = 0; i < acm->rx_buflimit; i++)
 			if (test_and_clear_bit(i, &acm->urbs_in_error_delay))
 					acm_submit_read_urb(acm, i, GFP_NOIO);
 	}