qcacmn: Fix the issues pointed out by KW in the regulatory module

Fix the issues pointed out by KW :

1) https://kwdbprod16.qualcomm.com:8070/review/insight-review.html#
   issuedetails_goto:problemid=222576,project=CRM_NHSS_QSDK_11_5_P

   Initialize dbg_id in reg_process_afc_power_event.

2) https://kwdbprod16.qualcomm.com:8070/review/insight-review.html#
   issuedetails_goto:problemid=222579,project=CRM_NHSS_QSDK_11_5_P

   In ucfg_reg_get_partial_afc_req_info, add a sanity check for afc_req
   to prevent NULL pointer dereference.

3) https://kwdbprod16.qualcomm.com:8070/review/insight-review.html#
   issuedetails_goto:problemid=222580,project=CRM_NHSS_QSDK_11_5_P

   Add a sanity check for afc_chan_obj to prevent NULL pointer
   dereference.

Change-Id: I0481fda6d08590312a863a33a1823a0b07fa194e
CRs-Fixed: 3043280

wmi/src/wmi_unified_tlv.c

@@ -13132,6 +13132,9 @@ static void copy_power_event(struct afc_regulatory_info *afc_info,
 		afc_chan_info = qdf_mem_malloc(power_info->num_chan_objs *
 					       sizeof(*afc_chan_info));
 
+		if (!afc_chan_info)
+			return;
+
 		copy_afc_chan_obj_info(afc_chan_info,
 				       power_info->num_chan_objs,
 				       channel_info_hdr,