brcmfmac: remove null-pointer check in .sched_scan_start() callback

In brcmf_cfg80211_sched_scan_start() the request parameter was checked
for being non-null. However, it never is so remove the check which gets
rid of following smatch warning:

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c:2904
brcmf_cfg80211_sched_scan_start()
warn: variable dereferenced before check 'request' (see line 2897)
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Piotr Haber <phaber@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c

@@ -3059,9 +3059,9 @@ brcmf_cfg80211_sched_scan_start(struct wiphy *wiphy,
 		return -EAGAIN;
 	}
 
-	if (!request || !request->n_ssids || !request->n_match_sets) {
+	if (!request->n_ssids || !request->n_match_sets) {
 		brcmf_err("Invalid sched scan req!! n_ssids:%d\n",
-			  request ? request->n_ssids : 0);
+			  request->n_ssids);
 		return -EINVAL;
 	}