tty: tty_port: Add a blank line after declarations

Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/tty_port.c

···
 		clear_bit(TTY_IO_ERROR, &tty->flags);
 		if (port->ops->activate) {
 			int retval = port->ops->activate(port, tty);
+
 			if (retval) {
 				mutex_unlock(&port->mutex);
 				return retval;