qcacmn: Check function pointer to avoid NULL point dereference

It calls spectral_process_phyerr of spectral operations without any
check. Which cause null point dereference potentially. So, check this
pointer before calling.

Change-Id: Iae246f847dd41e62b628223652a9527a65b43799
CRs-Fixed: 3055246

target_if/spectral/target_if_spectral.h

@@ -1732,6 +1732,10 @@ void target_if_spectral_process_phyerr(
 	}
 
 	p_sops = GET_TARGET_IF_SPECTRAL_OPS(spectral);
+	if (!p_sops->spectral_process_phyerr) {
+		spectral_err("null spectral_process_phyerr");
+		return;
+	}
 	p_sops->spectral_process_phyerr(spectral, data, datalen,
 					p_rfqual, p_chaninfo,
 					tsf64, acs_stats);