fix: coverity issues

CID: 399518

source/libs/function/src/tpercentile.c

@@ -492,7 +492,7 @@ double getPercentileImpl(tMemBucket *pMemBucket, int32_t count, double fraction)
 
         int32_t groupId = getGroupId(pMemBucket->numOfSlots, i, pMemBucket->times - 1);
         SIDList list = taosHashGet(pMemBucket->groupPagesMap, &groupId, sizeof(groupId));
-        assert(list->size > 0);
+        ASSERT(list != NULL && list->size > 0);
 
         for (int32_t f = 0; f < list->size; ++f) {
           SPageInfo *pgInfo = *(SPageInfo **)taosArrayGet(list, f);