[media] staging: lirc_serial: silence GCC warning

Building lirc_serial.o triggers this GCC warning:
drivers/staging/media/lirc/lirc_serial.c: In function '__check_sense':
drivers/staging/media/lirc/lirc_serial.c:1301:1: warning: return from incompatible pointer type [enabled by default]
This can be trivially fixed by changing the 'sense' parameter from bool
to int. But, to be safe, we also need to make sure 'sense' will only be
-1, 0, or 1. There's no need to document the new values that are now
allowed for the 'sense' parameter, since they're basically useless.

Signed-off-by: Paul Bolle <[e-mail]>
Cc: Jarod Wilson <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/staging/media/lirc/lirc_serial.c

···
 		}
 	}
 
+	/* make sure sense is either -1, 0, or 1 */
+	if (sense != -1)
+		sense = !!sense;
+
 	result = lirc_serial_init();
 	if (result)
 		return result;
···
 module_param(share_irq, bool, S_IRUGO);
 MODULE_PARM_DESC(share_irq, "Share interrupts (0 = off, 1 = on)");
 
-module_param(sense, bool, S_IRUGO);
+module_param(sense, int, S_IRUGO);
 MODULE_PARM_DESC(sense, "Override autodetection of IR receiver circuit"
 		 " (0 = active high, 1 = active low )");