char: xillybus: Fix spelling mistake "overflew" -> "overflowed"

There is a spelling mistake in a dev_err message. Fix it.
Acked-by: Eli Billauer <eli.billauer@gmail.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210601102201.8489-1-colin.king@canonical.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/char/xillybus/xillyusb.c

@@ -999,7 +999,7 @@ static int process_bulk_in(struct xillybuffer *xb)
 			return -EIO; /* We got really unexpected data */
 
 		if (bytes != fifo_write(fifo, p, bytes, xilly_memcpy)) {
-			dev_err(dev, "Misbehaving FPGA overflew an upstream FIFO!\n");
+			dev_err(dev, "Misbehaving FPGA overflowed an upstream FIFO!\n");
 			return -EIO;
 		}