tsdb tests: allocate more reasonable sample slice
Typical parameters are one hour  by 1 minute step, where the
function would allocate a slice of 3.6 million samples instead of 60.
@@ -678,7 +678,7 @@ func genSeriesFromSampleGenerator(totalSeries, labelCount int, mint, maxt, step
for j := 1; len(lbls) < labelCount; j++ {
lbls[defaultLabelName+strconv.Itoa(j)] = defaultLabelValue + strconv.Itoa(j)
}
- samples := make([]tsdbutil.Sample, 0, maxt-mint+1)
+ samples := make([]tsdbutil.Sample, 0, (maxt-mint)/step+1)
for t := mint; t < maxt; t += step {
samples = append(samples, generator(t))
}
