Input: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/joystick/db9.c

@@ -259,6 +259,7 @@ static unsigned char db9_saturn_read_packet(struct parport *port, unsigned char
 			db9_saturn_write_sub(port, type, 3, powered, 0);
 			return data[0] = 0xe3;
 		}
+		/* else: fall through */
 	default:
 		return data[0];
 	}
@@ -278,11 +279,14 @@ static int db9_saturn_report(unsigned char id, unsigned char data[60], struct in
 		switch (data[j]) {
 		case 0x16: /* multi controller (analog 4 axis) */
 			input_report_abs(dev, db9_abs[5], data[j + 6]);
+			/* fall through */
 		case 0x15: /* mission stick (analog 3 axis) */
 			input_report_abs(dev, db9_abs[3], data[j + 4]);
 			input_report_abs(dev, db9_abs[4], data[j + 5]);
+			/* fall through */
 		case 0x13: /* racing controller (analog 1 axis) */
 			input_report_abs(dev, db9_abs[2], data[j + 3]);
+			/* fall through */
 		case 0x34: /* saturn keyboard (udlr ZXC ASD QE Esc) */
 		case 0x02: /* digital pad (digital 2 axis + buttons) */
 			input_report_abs(dev, db9_abs[0], !(data[j + 1] & 128) - !(data[j + 1] & 64));
@@ -376,6 +380,7 @@ static void db9_timer(struct timer_list *t)
 			input_report_abs(dev2, ABS_X, (data & DB9_RIGHT ? 0 : 1) - (data & DB9_LEFT ? 0 : 1));
 			input_report_abs(dev2, ABS_Y, (data & DB9_DOWN  ? 0 : 1) - (data & DB9_UP   ? 0 : 1));
 			input_report_key(dev2, BTN_TRIGGER, ~data & DB9_FIRE1);
+			/* fall through */
 
 		case DB9_MULTI_0802: