qcacmn: dp: Replace explicit comparison to NULL

Per the Linux Kernel coding style, as enforced by the kernel
checkpatch script, pointers should not be explicitly compared to
NULL. Therefore within dp replace any such comparisons with logical
operations performed on the pointer itself.

Change-Id: I61f3adab1208682d36235421f44a048e35df346d
CRs-Fixed: 2418258

dp/wifi3.0/dp_rx_mon_dest.c

@@ -472,7 +472,7 @@ dp_rx_mon_mpdu_pop(struct dp_soc *soc, uint32_t mac_id,
 					  qdf_nbuf_data(msdu),
 					  (uint32_t)qdf_nbuf_len(msdu));
 
-			if (head_msdu && *head_msdu == NULL) {
+			if (head_msdu && !*head_msdu) {
 				*head_msdu = msdu;
 			} else {
 				if (last)
@@ -1103,7 +1103,7 @@ void dp_rx_mon_dest_process(struct dp_soc *soc, uint32_t mac_id, uint32_t quota)
 			break;
 		}
 
-		if (qdf_likely((head_msdu != NULL) && (tail_msdu != NULL))) {
+		if (qdf_likely((head_msdu) && (tail_msdu))) {
 			rx_mon_stats->dest_mpdu_done++;
 			dp_rx_mon_deliver(soc, mac_id, head_msdu, tail_msdu);
 		}