usb: cdc-wdm: Fix check for WWAN

CONFIG_WWAN_CORE was with CONFIG_WWAN in commit 89212e160b81 ("net: wwan:
Fix WWAN config symbols"), but did not update all users of it. Change it
back to use CONFIG_WWAN instead.

Fixes: 89212e160b81 ("net: wwan: Fix WWAN config symbols")
Cc: <[e-mail]>
Signed-off-by: Rikard Falkeborn <[e-mail]>
Acked-by: Oliver Neukum <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/class/cdc-wdm.c

···
 };
 
 /* --- WWAN framework integration --- */
-#ifdef CONFIG_WWAN_CORE
+#ifdef CONFIG_WWAN
 static int wdm_wwan_port_start(struct wwan_port *port)
 {
 	struct wdm_device *desc = wwan_port_get_drvdata(port);
···
 	/* inbuf has been copied, it is safe to check for outstanding data */
 	schedule_work(&desc->service_outs_intr);
 }
-#else /* CONFIG_WWAN_CORE */
+#else /* CONFIG_WWAN */
 static void wdm_wwan_init(struct wdm_device *desc) {}
 static void wdm_wwan_deinit(struct wdm_device *desc) {}
 static void wdm_wwan_rx(struct wdm_device *desc, int length) {}
-#endif /* CONFIG_WWAN_CORE */
+#endif /* CONFIG_WWAN */
 
 /* --- error handling --- */
 static void wdm_rxwork(struct work_struct *work)