core: pta: stats: Explicit when nexus heap stats is not applicable

Explicitly mention in the nexus heap statistics info when the
nexus heap is disabled. With this change, the information displayed
by `xtest --stats --alloc` better show why the printed values are all
0s for this pool.

Also force stats info to be 0 in case non-secure world did not clear
the passed shared buffer before invoking PTA stats.

Signed-off-by: Etienne Carriere <[email protected]>

core/pta/stats.c

@@ -79,14 +79,18 @@ static TEE_Result get_alloc_stats(uint32_t type, TEE_Param p[TEE_NUM_PARAMS])
 				sizeof(stats->desc));
 			break;
 
-#ifdef CFG_NS_VIRTUALIZATION
 		case ALLOC_ID_NEXUS_HEAP:
+#ifdef CFG_NS_VIRTUALIZATION
 			nex_malloc_get_stats(stats);
 			strlcpy(stats->desc, "KHeap", sizeof(stats->desc));
 			if (p[0].value.b)
 				nex_malloc_reset_stats();
-			break;
+#else
+			memset(stats, 0, sizeof(*stats));
+			strlcpy(stats->desc, "KHeap (disabled)",
+				sizeof(stats->desc));
 #endif
+			break;
 		case ALLOC_ID_RPMB:
 			if (rpmb_mem_stats(stats))
 				strlcpy(stats->desc,