[PATCH] HID: wacom: Mark expected switch fall-through

["Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>]

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

This patch fixes the following warning:

drivers/hid/wacom_wac.c: In function ‘wacom_setup_pen_input_capabilities’:
drivers/hid/wacom_wac.c:3506:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
   __clear_bit(ABS_MISC, input_dev->absbit);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hid/wacom_wac.c:3508:2: note: here
  case WACOM_MO:
  ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

This patch is part of the ongoing efforts to enable
-Wimplicit-fallthrough.

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
 drivers/hid/wacom_wac.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 72477e872324..5ecda99bf431 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -3504,6 +3504,7 @@ int wacom_setup_pen_input_capabilities(struct input_dev *input_dev,
 	switch (features->type) {
 	case GRAPHIRE_BT:
 		__clear_bit(ABS_MISC, input_dev->absbit);
+		/* fall through */
 
 	case WACOM_MO:
 	case WACOM_G4:
-- 
2.20.1