qcacld-3.0: Remove session_id from hdd_adapter

Originally struct hdd_adapter only used the legacy term session_id to
reference a session. To align with converged naming it was desirable
to change this to vdev_id. In order to ease the transition change
Id92b1a7bb9721564ba01184809fec98be2143545 ("qcacld-3.0: Alias vdev_id
to session_id in hdd_adapter") replaced the session_id field with a
union that contains both a session_id and a vdev_id field. Subsequent
changes replaced all session_id field references with vdev_id.

Now that all references to hdd_adapter field session_id have been
changed to vdev_id, remove the union that was previously added,
leaving behind just the vdev_id field.

Change-Id: I7a2e0812dcd9e9a9f229d1e310785710ab9d4acf
CRs-Fixed: 2393156

core/hdd/inc/wlan_hdd_main.h

@@ -1130,10 +1130,7 @@ struct hdd_adapter {
 	struct hdd_context *hdd_ctx;
 	struct wlan_objmgr_vdev *vdev;
 	qdf_spinlock_t vdev_lock;
-	union {
 	uint8_t vdev_id;
-	uint8_t session_id;
-	};
 
 	void *txrx_vdev;