[PATCH][next] Input: Fix fall-through warning for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a
warning by explicitly adding a fallthrough; statement.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
JFYI: We had thousands of these sorts of warnings and now we are down
      to just 13 in linux-next(20210607). This is one of those last
      remaining warnings. :)

 drivers/input/joystick/sidewinder.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/joystick/sidewinder.c b/drivers/input/joystick/sidewinder.c
index fac91ea14f17..8e9672deb1eb 100644
--- a/drivers/input/joystick/sidewinder.c
+++ b/drivers/input/joystick/sidewinder.c

@@ -660,6 +660,7 @@ static int sw_connect(struct gameport *gameport, struct gameport_driver *drv)
 					fallthrough;
 				case 45:				/* Ambiguous packet length */
 					if (j <= 40) {			/* ID length less or eq 40 -> FSP */
+					fallthrough;
 				case 43:
 						sw->type = SW_ID_FSP;
 						break;

-- 
2.27.0