wimax/i2400m/control: Mark expected switch fall-through

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

This patch fixes the following warning:

In file included from drivers/net/wimax/i2400m/debug-levels.h:30,

                 from drivers/net/wimax/i2400m/control.c:86:
drivers/net/wimax/i2400m/control.c: In function ‘i2400m_report_tlv_system_state’:
./include/linux/wimax/debug.h:200:4: warning: this statement may fall through [-Wimplicit-fallthrough=]
 do {         \
    ^
./include/linux/wimax/debug.h:404:36: note: in expansion of macro ‘_d_printf’
 #define d_printf(l, _dev, f, a...) _d_printf(l, "", _dev, f, ## a)
                                    ^~~~~~~~~

drivers/net/wimax/i2400m/control.c:354:3: note: in expansion of macro ‘d_printf’
d_printf(1, dev, "entering BS-negotiated idle mode\n");
^~~~~~~~
drivers/net/wimax/i2400m/control.c:355:2: note: here
case I2400M_SS_DISCONNECTING:
^~~~

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

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

---
 drivers/net/wimax/i2400m/control.c | 1 +
 1 file changed, 1 insertion(+)

index ef298d8525c5..4fe7c7e132c4 100644
@@ -352,6 +352,7 @@ void i2400m_report_tlv_system_state(struct i2400m *i2400m,
 
 	case I2400M_SS_IDLE:
 		d_printf(1, dev, "entering BS-negotiated idle mode\n");
+		/* Fall through */
 	case I2400M_SS_DISCONNECTING:
 	case I2400M_SS_DATA_PATH_CONNECTED:
 		wimax_state_change(wimax_dev, WIMAX_ST_CONNECTED);

2.21.0

From: "Gustavo A. R. Silva" <[email protected]>
Date: Wed, 24 Apr 2019 11:20:16 -0500

...

Applied.