fixup: neigh_meas_avg: detect invalid window size as <=0, log if invalid

Change-Id: I8c5d0642aeb4fbee73a035b9f73cf3a09b1bcf90
diff --git a/src/libbsc/handover_decision.c b/src/libbsc/handover_decision.c
index 04ca144..1ad4b36 100644
--- a/src/libbsc/handover_decision.c
+++ b/src/libbsc/handover_decision.c
@@ -103,8 +103,10 @@
 	if (window < nmp->rxlev_cnt)
 		window = nmp->rxlev_cnt;
 	/* this should never happen */
-	if (window == 0)
+	if (window <= 0) {
+		LOGP(DHO, LOGL_ERROR, "Requested Neighbor RxLev for invalid window size of %d\n", window);
 		return 0;
+	}
 
 	idx = calc_initial_idx(ARRAY_SIZE(nmp->rxlev),
 				nmp->rxlev_cnt % ARRAY_SIZE(nmp->rxlev),