USB: serial: console: add support for flow control

Add support for enabling hardware flow control using the 'r' command
line option.

This also avoids a W=1 (-Wunused-but-set-variable) warning.

Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>

drivers/usb/serial/console.c

···
 		if (*s)
 			doflow = (*s++ == 'r');
 	}
-	
+
 	/* Sane default */
 	if (baud == 0)
 		baud = 9600;
···
 		cflag |= PARENB;
 		break;
 	}
+
+	if (doflow)
+		cflag |= CRTSCTS;
 
 	/*
 	 * no need to check the index here: if the index is wrong, console