staging: r8822be: fix null pointer dereference with a null driver_adapter

The call to _rtl_dbg_trace via macro HALMAC_RT_TRACE will trigger a null
pointer deference on the null driver_adapter. Fix this by assigning
driver_adapter earlier to halmac_adapter->driver_adapter before the tracing
call so that a non-null driver_adapter is passed instead.

Detected by CoverityScan, CID#1454613 ("Explicit null dereferenced")

Fixes: 938a0447f094 ("staging: r8822be: Add code for halmac sub-driver")
Signed-off-by: Colin Ian King <[e-mail]>
Acked-by: Larry Finger <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtlwifi/halmac/halmac_88xx/halmac_api_88xx.c

···
 {
 	u8 h2c_buff[HALMAC_H2C_CMD_SIZE_88XX] = {0};
 	u16 h2c_seq_mum = 0;
-	void *driver_adapter = NULL;
+	void *driver_adapter = halmac_adapter->driver_adapter;
 	struct halmac_api *halmac_api;
 	struct halmac_h2c_header_info h2c_header_info;
 	enum halmac_ret_status status = HALMAC_RET_SUCCESS;
···
 	HALMAC_RT_TRACE(driver_adapter, HALMAC_MSG_H2C, DBG_DMESG,
 			"[TRACE]halmac_p2pps !!\n");
 
-	driver_adapter = halmac_adapter->driver_adapter;
 	halmac_api = (struct halmac_api *)halmac_adapter->halmac_api;
 
 	P2PPS_SET_OFFLOAD_EN(h2c_buff, p2p_ps->offload_en);